Board Review Flashcards

Question

Any class medical certificate can be issued to an individual with an implantable defibrillator. a. True b. False

Answer 1

B. The following conditions must be deferred: 1. Hypertrophic Cardiomyopathy, 2. Non-compaction cardiomyopathy, 3. Cardiac Transplant, 4. Cardiac decompensation, 5. Congenital heart disease, 6. Hypertrophy, 7. Pericarditis, endocarditis, or myocarditis, 8. Cardiac enlargement or other evidence of cardiovascular abnormality, 9. Anti-tachycardia devices, 10. Implantable defibrillators, 13.Any other cardiac disorder not otherwise covered in this section, 14. Hypotension {AME Guide, Item 36, Other Cardiac Conditions}

Answer 2

F. Diabetes is NOT a CACI. CACIs with Certification Worksheets: ARTHRITIS, ASTHMA, BLADDER CANCER, BREAST CANCER, CHRONIC IMMUNE THROMBOCYTOPENIA (c-ITP), CHRONIC KIDNEY DISEASE, CHRONIC LYMPHOCYTIC LEUKEMIA (CLL)/ SMALL LYMPHOCYTIC LYMPHOMA (SLL), COLITIS, COLON CANCER/COLORECTAL CANCER, ESSENTIAL TREMOR, GLAUCOMA, HEPATITIS C – CHRONIC, HYPERTENSION, HYPOTHYROIDISM, MIGRAINE AND CHRONIC HEADACHE, MITRAL VALVE REPAIR, PRE-DIABETES, PRIMARY HEMOCHROMATOSIS, PROSTATE CANCER, RENAL CANCER, RETAINED KIDNEY STONE(S), TESTICULAR CANCER {AME Guide, CACI Conditions}

Answer 3

C. Inclination is the angle between Earth’s equatorial plane and the plane of a spacecraft’s orbit. Launching straight eastward (posigrade) to receive velocity assist from Earth’s rotation, attains an orbital inclination equal to the launch site’s latitude. Kennedy Space Center is 28 degrees. 62 degrees is the maximum inclination of any Space Shuttle mission. The inclination of the desired orbit cannot be lower than the launch site latitude without a significant performance penalty. The orbital inclination of 51.6 degrees for the ISS is defined by the Russian launch, range, and tracking capabilities and must be accommodated by the lower-latitude US, Japanese, and European launch sites. {Barratt (2019), p. 7}

Answer 4

d. In the exercise of its sovereignty, it is for each State to consent (or not) to be bound by these international regulations. Consequently, each WHO Member State as well as each ICAO Contracting State is at liberty not to comply with the IHR or parts thereof, provided it notifies WHO and ICAO of its reservations and differences, including "not bound", if it so wishes. “Under Articles 21(a) and 22, the Constitution of WHO confers upon the World Health Assembly the authority to adopt regulations ‘designed to prevent the international spread of disease’ which, after adoption by the Health Assembly, enter into force for all WHO Member States that do not affirmatively opt out of them within a specified time period” Annex 9 to the Chicago Convention (1944) requires that member states establish a national aviation preparedness plan, provide first aid at airports, require the pilot in command (PIC) to inform air traffic control of suspected communicable disease on board, and establish a revised list of signs and symptoms indicative of a communicable disease included in the health part of the aircraft general declaration. {Davis (2022), p. 739}

Answer 5

a. There are no specific FAA rules governing aircrew qualifications for patient transportation. In general, the FAA regulates aviation safety, while the states regulate medical care. The aircrew must meet FAA requirements for a similar flight handling cargo, but there are no requirements related to patient transportation, patient equipment, or patient attendants. Although medical attendants are required to meet a variety of credentialing and certification requirements by state and local governments or hospitals, depending on the contractor and the location of the service provided, they are considered air passengers by the FAA. In the United States, the FAA regulates air ambulance services under 14 CFR Part 135, which governs operations of helicopter aircraft as well as operations of unscheduled or commuter fixed-wing aircraft for compensation or hire. However, some fixed-wing operations operate under Part 121 (scheduled commercial air service). The 14 CFR Part 119 also provides some specific, additional requirements for air ambulance operations. These U.S. federal regulations do not cover training, medical capabilities, or clinical care provided by the medical “back-end” crew, nor do they provide guidance as to which types of patients should appropriately be transported. Rather, medical issues deal mostly with crew rest. These are covered specifically in 14 CFR, paragraphs 135.267 and 135.271. New guidance was released on February 20, 2014, for HEMS operators; however, the initiatives focused on flight operations safety because of recent aircraft mishaps, rather than addressing patient care during transport. {Davis (2022), p. 713}

Answer 6

d. FAR 91.211 requires that supplemental oxygen be USED at cabin pressure altitudes above 12,500 feet (MSL) up to 14,000 feet (MSL) by the minimum flight crew for all portions of the flight at these altitudes of more than 30 minutes duration; the minimum flight crew must be provided and USE supplemental oxygen for the entire flight time above 14,000 feet (MSL); and at flight altitudes of 15,000 feet (MSL) all aircraft occupants must be PROVIDED with supplemental oxygen. Symptoms of hypoxia should be expected to be present at altitudes considerably lower than is reflected in these recommendations. A diminished capacity to see dim objects begins below 7,500 feet (MSL). Night vision is reduced as a result. Symptoms involving mental function may appear at less-than 10,000 feet (MSL). For reasons of flying safety, recommendations for use of supplemental oxygen should include day use above 10,000 feet and night use above 5,000 feet to give a good physiologically safe margin.

Answer 7

a. Certified airports are required to have a full scale drill of their emergency plan every 3 years, and an annual meeting to review the plan with all the involved parties. The Joint Commission on Accreditation of Health Organizations requires a written plan and a twice yearly drill for hospitals. Most plans use the ICS as a framework for control of a disaster. It was devised in the early 1970's. The Fire and Rescue personnel are the incident commanders with chiefs of finance, logistics, operations, and planning. References: 1) Mahoney BD. Disaster Medical Services. In: Tintinalli J, Rothstein RJ, Krome RL, eds. Emergency Medicine: A Comprehensive Study Guide. American College of Emergency Physicians. New York City: McGraw-Hill, 1992. 2) Part 139: Code of Federal Regulations, Volume 14. National Archives and Records Administration, Washington DC.

Answer 8

b. Most controllers do not have college educations when they enter air traffic work and research has shown that college experience is not a good predictor of performance. Each of the other factors is used in the selection. Research has shown that job success following entry into air traffic work after the age of 30 is unlikely; thus individuals above that age are not accepted for air traffic training. Overall level of personal adjustment is assessed both during the examination by the aviation medical examiner and by the use of the 16 PF test. Individuals flagged by these screening devices are referred for additional psychiatric and psychological evaluation as appropriate. Persons who have had previous air traffic control experience (usually military), are sometimes given advanced employment standing. References: 1) Cobb BB. The Relationship of Chronological Age, Length of Experience, and job Performance Ratings of Air Route Traffic Control Specialists. Aerospace Med 1968;39:119-124. 2) Cobb BB, Young CI, Rizzuti BL. Education as a Factor in the Selection of Air Traffic Controller Trainees. Washington DC: FAA Office of Aviation Medicine, 1976, Report No. FAA-AM-76-6. 3) Mathews JJ, Cobb BB. Relationships Between Age, ATC, Experience and Job Ratings of Terminal Area Air Traffic Controllers. Aerospace Med 1974;4556-60.

Answer 9

C. In an NTSB survey of all US air carrier accidents during the interval 1983-2000, there were 51,207 occupants involved, of these there were 2,280 fatalities (4.3%). For accidents classified as "serious" - where fire, serious injury, or substantial or complete destruction of the aircraft occurred - 55.6% of the occupants survived. In accidents where the crash forces were considered survivable and the immediate surrounding area of the passengers was preserved, the survival rate was 76.6%. Public perception is that aircraft accidents are more lethal than the data supports. High visibility crashes gain more media attention, and usually involve crashes where all occupants are killed. These are exceptional cases, and many other accidents, fitting the ICAO definition of an accident, occur where most or all passengers survive the accident. Reference: NTSB Safety Report, SR-01/01, March 2001.

Answer 10

d. Low-molecular weight heparin is an appropriate therapy for DVT risk and may be indicated in passengers with a history of prior DVTs, pulmonary embolus or concomitant risk factors. Despite earlier reports of "economy class syndrome" (Symington & Stack, 1977), the association of commercial air travel with DVT is circumstantial at best. A recent study, the WHO Research into Global Hazards of Travel (WRIGHT) found that the DVT risk doubled in flights over 4 hours, but this was not unique to air travel but seen in other travel situations where passengers are exposed to prolonged seated immobility. Despite frequent exposure to cabin altitude and prolonged sitting, ATP pilots have not been shown to have any increased risk of DVT. Likewise the dry cabin atmosphere and relatively lower partial pressure of oxygen at cabin altitudes of 6000-8000ft. have not been shown to elevate DVT risk. Aspirin therapy for passengers has not been shown to be of benefit in preventing DVT, may carry substantial risks of side effects, and is not recommended.

Answer 11

d. In a Michigan study of structurally survivable, fatal accidents, 80% of the fatally injured had received head trauma. It has been estimated that approximately 80% of the deaths and serious injuries in the survivable Michigan aircraft accidents investigated could have been prevented by use of an adequate upper torso restraint system. Reference: Snyder, RG. 1978, General Aviation Crash Survivability, Technical paper, series #7800 17. Society of Automotive Engineers, Inc. Warrendale, PA, pp 3-12.

Answer 12

a. The body can withstand larger impact decelerative forces in a perpendicular (eyeballs in/out; +/- G×) direction than either the lateral (Gy direction) or along the longitudinal axis (G direction). This is due primarily to the larger area of the body available for distribution of forces in the Gx direction, and also better suspension of the internal viscera in the perpendicular direction. Lower rates of G onset are tolerated better than high rates of onset. For example, a 1,000 G/sec onset rate may produce shock whereas an impact of similar magnitude but slower onset rate of 60 G/sec will not. A longer duration of crash forces reduces the magnitude of forces tolerated, e.g. forward acceleration of 45 G can be tolerated for 0.044 secs, whereas a pulse of 0.2 secs reduces tolerance magnitude to 25 Gs. The use of resilient cushions will actually result in higher decelerative forces than the craft is subject to. This is the concept of dynamic overshoot. There is a catch-up period which causes the body's accelerative forces to catch up to the airframe in a very short period.

Answer 13

C. Lung cancer is the leading cause of cancer death in the United States overall, followed by colorectal cancer. Prostate cancer and breast cancer are the second leading causes of cancer death in men and women, respectively, (but not overall). {National Cancer Institute—https://seer.cancer.gov/statfacts/html/common.html}

Answer 14

A. The US Preventive Services Task Force recommends annual screening for lung cancer with low- dose computed tomography (LDCT) in adults aged 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once the person has quit smoking for at least 15 years or if their health significantly limits their life expectancy or ability to undergo curative lung cancer surgery. Grade B. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening}

Answer 15

A. Two large studies conducted outside of the U.S. demonstrated no mortality benefit for teaching self breast examinations. Additionally, teaching self breast examination resulted in an increase in imaging studies and biopsies {Kösters JP, Gøtzsche PC. Regular self‐examination or clinical examination for early detection of breast cancer. Cochrane Database of Systematic Reviews 2003, Issue 2. Art. No.: CD003373. DOI: 10.1002/14651858.CD003373. Accessed 19 September 2023.}

Answer 16

D. The decision to initiate low-dose aspirin use for the primary prevention of CVD in adults aged 40 to 59 years who have a 10% or greater 10-year CVD risk should be an individual one. Evidence indicates that the net benefit of aspirin use in this group is small. Persons who are not at increased risk for bleeding and are willing to take low-dose aspirin daily are more likely to benefit. Grade C. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/aspirin-to-prevent-cardiovascular-disease-preventive-medication}

Answer 17

C. The U.S. Preventive Services Task Force recommends a biennial screening mammogram from women age 50 to 74 years. Grade B. While no studies have directly evaluated the benefit of an annual versus biennial mammogram, a decision analysis projected that 70% to 99% of the benefit of annual screening would be obtained, with a significant reduction in the number of mammograms required and therefore a decreased risk for harms (49% of women who have 10 mammograms have a false positive, potentially requiring a biopsy or surgery). {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/breast-cancer-screening}

Answer 18

D. According to the JNC VII recommendations, the treatment goal for average risk patients with hypertension is 140/90. The treatment goal reflects the value above which medications should be considered. The treatment goal for patients with diabetes or renal disease is <130/80. Prehypertension is a blood pressure between 121-139/81-89. {https://www.nhlbi.nih.gov/sites/default/files/media/docs/jnc7full.pdf}

Answer 19

D. Routine screening can be discontinued at age 65 years and after a total hysterectomy for benign disease. The USPSTF recommends against screening for cervical cancer in women who have had a hysterectomy with removal of the cervix and do not have a history of a high-grade precancerous lesion (ie, cervical intraepithelial neoplasia [CIN] grade 2 or 3) or cervical cancer. Grade D. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/cervical-cancer-screening}

Answer 20

D. ARCHIVED RECOMMENDATION: The USPSTF strongly recommends screening women aged 45 and older for lipid disorders if they are at increased risk for coronary heart disease. (Grade A) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/lipid-disorders-in-adults-cholesterol-dyslipidemia-screening-2008#:~:text=The%20USPSTF%20strongly%20recommends%20screening,and%20older%20for%20lipid%20disorders.&text=The%20USPSTF%20strongly%20recommends%20screening%20women%20aged%2045%20and%20older,risk%20for%20coronary%20heart%20disease.}

Answer 21

A. The U.S. Preventive Services Task Force considers: (1) the burden of suffering from the target condition, (2) accuracy of screening tests, and (3) the benefits of treatments to make an overall determination of whether early intervention leads to better outcomes than treatment of symptomatic disease. These benefits are compared against harms, such as the downstream consequences of screening, to decide if the benefits of screening outweigh the harms. Cost, cost effectiveness, insurance coverage, and liability are not considered.

Answer 22

A. Theoretically genetic tests can be used for population screening, gene therapy, pharmacogenetics, and predicting and diagnosing common and uncommon diseases. To date, the greatest use has been for diagnosing uncommon diseases. Genetic tests have unique issues, including the risk of diagnosing conditions in family members who have not consented for testing (e.g., diagnosing Huntington’s Chorea, an autosomal dominant condition, in a grandfather and grandson means that the father also has the condition). The type of history required for genetic testing and counseling is much more in depth than what is typically obtained in the primary care setting. As a result, the U.S. Preventive Services Task Force recommends referring patients with a family history suggesting increased risk from breast cancer to a genetic counselor. It is possible that this could be done by a trained primary care physician.

Answer 23

B. The primary risk factors for prostate cancer include (1) being a man >50 years of age, being (2) African American, and (3) having a first degree relative with prostate cancer. Co-morbidities such as diabetes do not alter risks for prostate cancer. Having benign prostatic hypertrophy, which causes urinary hesitancy and nocturia, does not increase the risk of prostate cancer. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/prostate-cancer-screening}

Answer 24

C. The U.S. Preventive Services Task Force recommends a one-time screening for abdominal aortic aneurysms in men age 65 years and older who have ever smoked (“B” recommendation). {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/abdominal-aortic-aneurysm-screening} The Task Force has concluded that there is insufficient evidence to assess benefits and harms of screening for osteoporosis in men (“I” recommendation); insufficient evidence to assess benefits and harms of screening for type 2 diabetes in asymptomatic adults with blood pressure 135/80 mm Hg or lower (I” recommendation); and recommends against screening for asymptomatic carotid artery stenosis in the general adult population (“D” recommendation). NOTE: quoted diabetes screening recommendation is ARCHIVED from 2008. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/diabetes-mellitus-type-2-in-adults-screening-2008} B is also correct: The USPSTF recommends screening for prediabetes and type 2 diabetes in adults aged 35 to 70 years who have overweight or obesity. Clinicians should offer or refer patients with prediabetes to effective preventive interventions. (Grade B) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/screening-for-prediabetes-and-type-2-diabetes}

Answer 25

A. The USPSTF recommends screening for osteoporosis with bone measurement testing to prevent osteoporotic fractures in women 65 years and older and in postmenopausal women younger than 65 years who are at increased risk of osteoporosis, as determined by a formal clinical risk assessment tool. (Grade B) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/osteoporosis-screening} The Task Force recommends against routine screening abdominal aortic aneurysm in women (“D” recommendation) and screening for asymptomatic carotid artery stenosis in the general adult population (“D” recommendation). The Task Force states that there is insufficient evidence to assess benefits and harms of screening for type 2 diabetes in asymptomatic adults with blood pressure 135/80 mm Hg or lower (I” recommendation). NOTE: quoted diabetes screening recommendation is ARCHIVED from 2008.

Answer 26

A. The USPSTF recommends screening for hypertension in adults 18 years or older with office blood pressure measurement (OBPM). The USPSTF recommends obtaining blood pressure measurements outside of the clinical setting for diagnostic confirmation before starting treatment. (Grade A). {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/hypertension-in-adults-screening} The USPSTF recommends screening for prediabetes and type 2 diabetes in adults aged 35 to 70 years who have overweight or obesity. Clinicians should offer or refer patients with prediabetes to effective preventive interventions. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/screening-for-prediabetes-and-type-2-diabetes} The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for thyroid dysfunction in nonpregnant, asymptomatic adults. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/thyroid-dysfunction-screening}

Answer 27

D. The USPSTF recommends against screening for testicular cancer in adolescent or adult men. (Grade D) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/testicular-cancer-screening} No current recommendation regarding clinical breast examination. It was Grade I on the archived 2009 recommendation. {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/breast-cancer-screening} For men aged 55 to 69 years, the decision to undergo periodic prostate-specific antigen (PSA)-based screening for prostate cancer should be an individual one. (Grade C) The USPSTF recommends against PSA-based screening for prostate cancer in men 70 years and older. (Grade D) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/prostate-cancer-screening} The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of visual skin examination by a clinician to screen for skin cancer in adolescents and adults. (Grade I) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/skin-cancer-screening}

Answer 28

A. Globally, infectious diseases, including acute respiratory infections, diarrhoea and malaria, along with pre-term birth complications, birth asphyxia and trauma and congenital anomalies remain the leading causes of death for children under 5. {https://www.who.int/data/gho/data/themes/topics/topic-details/GHO/child-mortality-and-causes-of-death} The proportion of global disease mortality for children under age 1-5 years from 2000-2019 in descending order for each category is: (1) lower respiratory infections—10.1% (2) diarrhea—8.5% (3) malaria—7.8% (4) injury—4.7% (5) measles—3.5% (6) congenital abnormalities—3.2% (7) tuberculosis—2.5% (8) meningitis—1.4% (9) preterm birth complications—1.1% (10) AIDS—1.0% {https://www.thelancet.com/journals/lanchi/article/PIIS2352-4642(21)00311-4/fulltext}

Answer 29

B. Mothers who are both Hepatitis B surface and “e” antigen positive have the highest viral loads. About 70%-90% of infants born to these mothers become infected without intervention. Of those who are only surface antigen positive, about 20% of infants become infected. In either case, 90% of infected infants will become a lifetime carrier of Hepatitis B. Presence of antibody to either core or surface antigen reflects recovery and immunity to infection. No transmission to an infant would be expected in these scenarios. HBsAg: active infection HBsAb: recovered HBcAb IgM: early marker of infection HBcAb IgG: best marker of prior infection HBeAg: high infectivity HBeAb: low infectivity

Answer 30

A. Yellow fever and shingles vaccine are both live viral immunizations. According to the US Advisory Committee on Immunization Practices (ACIP) general recommendations on immunizations and statement on yellow fever vaccination, it is best to wait about 30 days between two live virus vaccinations to maximize the immune response for each, though simultaneous vaccination is acceptable. Giving yellow fever vaccine after 2 weeks would be too soon in the scenario described. The second dose of Hepatitis A vaccine is recommended 6 months after the first, and 95% have adequate immunity after the first dose. Yellow Fever vaccine should optimally be given at least 10 days before the anticipated exposure in the endemic country.

Answer 31

B. Azithromycin at this dosage would cover both gonorrhea and Chlamydia. Ceftriaxone only treats gonorrhea. Since up to 30% of those with gonorrheal infection are co-infected with Chlamydia those patients often require a second antibiotic. Fluoroquinolones are no longer recommended as first line treatment for gonorrhea due to increasing resistance by the organism. Doxycycline is effective against Chlamydia but not gonorrhea.

Answer 32

D. An IGRA is preferred for testing persons that previously had BCG immunization (as a vaccine or for cancer therapy). Use of IGRAs in this population is expected to increase diagnostic specificity and improve acceptance of treatment for LTBI. TST is preferred for testing children under age 5 years. Either a TST or IGRA is acceptable for serial testing in an occupational setting where workers may be at increased risk for exposure to tuberculosis, although initial two-step testing must be done with TST whereas a single test is sufficient at start with an IGRA (but may be more expensive). In a patient who may be immune suppressed due to drugs or other causes such as chronic illness, without a diagnostic “gold standard” for LTBI, the accuracies of both the TST and the IGRAs are suspect and neither may be recommended over the other.

Answer 33

D. Smallpox is transmitted only human to human. The lack of an animal reservoir made it particularly convenient for eradication through smallpox vaccination. Marburg virus transmission has been linked with monkeys and its natural reservoir may be fruit bats. Tularemia has been transmitted by hunting and skinning rabbits and other animals or through fleas or ticks, and plague has been spread from rodents and fleas to humans.

Answer 34

C. The LD50 (lethal dose 50%) is defined as the dose causing death in 50% of test animals which occurred in this case with a dose of 100 mg. LOEL stands for “lowest observable effect level,” indicating the lowest dose at which a specified effect is first observed. NOAEL stands for “no observable adverse effect level,” indicating the highest dose at which no adverse effects are observed.

Answer 35

C. The stages of carcinogenesis are (1) initiation—process in which DNA damage predisposes a tissue to carcinogenesis; (2) promotion—process by which the initiated cells are exposed to substances called promoters that confer a selective growth advantage of the initiated cells over normal cells; and (3) progression—the process of clonal expansion of the initiated cells

Answer 36

A. Lead primarily affects blood cells and the nervous system, leading to encephalopathy and peripheral nerve dysfunction. Mercury is also a neurotoxin and nephrotoxin, but is not associated with increased risk of lung cancer. Asbestos is associated with increased risk of lung cancer and mesothelioma, but not leukemia. Hepatitis A is an acute liver infection not associated with chronic effects, in contrast to Hepatitis B, which results in chronic infection, particularly when primary infection occurs early in life.

Answer 37

B. The first step in disaster response is to complete a rapid needs assessment for the affected area(s). This can be completed through structured cluster sampling models or other methods to characterize the population(s) at risk, and to identify and prioritize actions needed to reduce imminent risks to public health.

Answer 38

C. The summation of weighted tissue equivalent doses represents the effective dose (E), which is used to determine the long-term risk associated with radiation exposure. Both equivalent and effective doses are measured in sievert (Sv), expressed in units of J/kg. The Sv corresponds to the non-SI unit of roentgen equivalent man (rem) whereby 1 rem is equivalent to 0.01 Sv. These values are therefore calculated, rather than directly measured, for the purposes of estimating the long-term risk of stochastic effects associated with radiation exposure. Stochastic risks are those that are probabilistic in nature, such as carcinogenesis and hereditary effects. The annual exposure limit for US astronauts is 0.5 Sv (500 mSv). A total body exposure to 5 Sieverts (Sv) would result in hematopoetic syndrome. Hematopoietic, 2.5-10 Sv, latency 2-3 wks, bone marrow necrosis Gastrointestinal, 10-50 Sv, latency 1 wk, mucosal cell necrosis Acute incapacitation, >50 Sv, latency 3 hrs, unknown cellular event Hematopoietic and GI have similar 48-72 hour prodromal phases. In the first 24 hours health effects would consist of nausea and vomiting. The principle phase of hematopoietic would follow 1-6 weeks later, resulting in bone marrow damage, petechia, purpura, and bleeding from mucus membranes, followed by a period of recovery. The principle phase of GI may present with fever. The principle phase of acute presents with coma and death. {Davis (2019), pp. 41, 46, & 76}

Answer 39

B. According to the US Centers for Disease Control and Prevention, malarone (atovaquone and proguanil) is the agent of choice for travelers to Africa. Resistance to chlororoquine has rendered it ineffective as an anti-malarial agent except in specific countries in Central and South America and the Middle East. Ciprofloxacin and Azithromycin are not anti-malarial agents but may be used for self-treatment of travelers’ diarrhea. {https://wwwnc.cdc.gov/travel/yellowbook/2024/infections-diseases/malaria}

Answer 40

A. The Occupational Safety and Health Administration (OSHA) requires that employers report fatalities within eight (8) hours after the death of any employee from a work-related incident or the in-patient hospitalization of three or more employees as a result of a work-related incident. An in-patient hospitalization, amputation, or eye loss must be reported within 24 hours. The report must be communicated orally by telephone or in person to the Area Office of OSHA, U.S. Department of Labor, that is nearest to the site of the incident. {https://www.osha.gov/report#:~:text=All%20employers%20are%20required%20to,be%20reported%20within%2024%20hours.}

Answer 41

D. Although many vaccines are recommended for travelers to certain destinations, only Yellow Fever and Meningococcal vaccines are required for specific destinations. Proof of Yellow Fever vaccination is required for travelers to certain countries and regions in South America and Africa. Proof of Yellow Fever Vaccination is also required for entry into countries following travel to countries with endemic Yellow Fever. Proof of Meningococcal vaccination is required for travelers who are participating in the Haaj pilgrimage to Saudia Arabia.

Answer 42

B. The National Health and Nutrition Examination Survey (NHANES), a survey of a representative sample of the U.S. population, includes in-person interviews and standardized physical assessment of survey respondents facilitated by a mobile examination unit. The National Survey of Drug Use and Health (NSDUH) involves in-home interviews, but does not include physical assessment. The Behavioral Risk Factor Surveillance System (BRFSS)—a telephone-based survey—and the Youth Risk Behavior Survey (YRBS)—a school-administered survey—do not involve physical assessment.

Answer 43

B. The Health Belief Model incorporates six key constructs in behavior change: (1) perceived susceptibility (subjective perception of risk of contracting disease), (2) perceived severity (feelings about the seriousness of getting the disease--or leaving it untreated), (3) perceived benefit (beliefs about the effectiveness of options available to reduce the disease threat), (4) perceived barriers (negative aspects of a health action that impede adopting the recommended behavior changes), (5) cues to action (events or stimuli to “trigger” one’s “readiness” to change), and (6) self-efficacy (confidence in one’s ability to take action and succeed).

Answer 44

B. According to the 2020 NSDUH, 22.2% of respondents 12 or older reported binge alcohol use in past month. 50% reported any alcohol in past month. {https://www.samhsa.gov/data/sites/default/files/reports/rpt35325/NSDUHFFRPDFWHTMLFiles2020/2020NSDUHFFR1PDFW102121.pdf#page16} [OLD DATA] 23% of those responding to the survey reported binge drinking, defined as having 5 or more drinks on one occasion. 46% of adults >21 years reported drinking no alcohol, 26% report drinking less than 1 drink per week,13% report having approx. 1 drink/day, 9% approx. 2 drinks/day and 6% report drinking more than 2 drinks/day.

Answer 45

B. Alcohol pricing and taxation, health warnings on alcohol product packaging, and penalties for drinking and driving have been shown to reduce alcohol drinking. According to Community Preventive Services Task Force, increasing alcohol taxes is recommended on strong evidence {https://www.thecommunityguide.org/pages/task-force-findings-excessive-alcohol-consumption.html} According to CDC penalties for drinking and driving are effective {https://www.cdc.gov/transportationsafety/impaired_driving/strategies.html}

Answer 46

D. The BRFSS is a telephone survey designed by the Centers for Disease Control and Prevention (CDC) and conducted by state health agencies to assess behavioral risk factors and use of preventive health services. It does not address marijuana or other illicit drug use. {https://www.cdc.gov/brfss/index.html}

Answer 47

C. Pharmacological and psychological treatments individually are effective in approximately 50% of patients who are followed up in short-term studies (few studies follow patients beyond 12 months). When combined, efficacy is demonstrated in approximately two-thirds of patients. Pharmacological treatments offer only approximately 15% to 20% additional benefit over placebo. We found clear indications that a combined treatment including psychotherapy is more effective than pharmacotherapy alone. Although the effect size indicating the difference between pharmacotherapy and the combined therapy was small, it was highly statistically significant. This suggests that psychotherapy has an additional effect on depression apart from the effects of pharmacotherapy. {PMID: 19818243. https://www-psychiatrist-com.yale.idm.oclc.org/jcp/depression/adding-psychotherapy-pharmacotherapy-treatment-depressive/}

Answer 48

C. The Theory of Reasoned Action emphasizes a person’s behavioral intention. Behavioral intention is determined by positive or negative attitudes towards performing the behavior and one’s normative beliefs about whether influential others approve or disapprove of performing the behavior. The Health Belief Model incorporates several key constructs in behavior change: one’s perception of barriers to and benefits of taking an action, level of self-efficacy to conduct the action, and cues to action. The Social Learning Theory says that behavior is explained in terms of a dynamic interaction of personal, environmental and behavior influences (reciprocal determinism). People learn not only via their own interactions with the environment, but from observing others (observational learning). The other constructs in this theory include behavioral capability, expectations, and self-reinforcement. The Transtheoretical Model addresses the stages of behavior change: pre-contemplation, contemplation, preparation, action, maintenance, and termination.

Answer 49

D. For the precontemplation stage, the appropriate action is discussing the risks of an unhealthy behavior. For the contemplation stage, the appropriate response is to offer personalized assessment of the patient’s risk. For the preparation stage, patients are ready to develop an action plan. Specifically for smoking cessation, the action plan should include a quit date. During preparation they also need additional information and resources to assist them in making the change. For the action and maintenance stages, encouragement for sustaining the behavior is appropriate, as well as relapse prevention planning.

Answer 50

A. The USPSTF recommends screening for unhealthy alcohol use in primary care settings in adults 18 years or older, including pregnant women, and providing persons engaged in risky or hazardous drinking with brief behavioral counseling interventions to reduce unhealthy alcohol use. (Grade B) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/unhealthy-alcohol-use-in-adolescents-and-adults-screening-and-behavioral-counseling-interventions} The USPSTF recommends that clinicians individualize the decision to offer or refer adults without cardiovascular disease risk factors to behavioral counseling interventions to promote a healthy diet and physical activity. (Grade C) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/healthy-lifestyle-and-physical-activity-for-cvd-prevention-adults-without-known-risk-factors-behavioral-counseling} The USPSTF recommends counseling young adults, adolescents, children, and parents of young children about minimizing exposure to ultraviolet (UV) radiation for persons aged 6 months to 24 years with fair skin types to reduce their risk of skin cancer. (Grade B) The USPSTF recommends that clinicians selectively offer counseling to adults older than 24 years with fair skin types about minimizing their exposure to UV radiation to reduce risk of skin cancer. Existing evidence indicates that the net benefit of counseling all adults older than 24 years is small. In determining whether counseling is appropriate in individual cases, patients and clinicians should consider the presence of risk factors for skin cancer. (Grade C) {https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/skin-cancer-counseling}

Answer 51

B. The Rothman typology incorporates social planning, social action and locality development. Rothman identifies a category of community practice which he calls social action which organizes groups of people to influence political processes. These actions are designed to change the balance of power between one group and their opposition. Social planning refers to the role that policy planners and analysts play in social change. Locality development describes community development in which residents develop and manage social and physical service delivery within their own community. According to Rothman, locality development also includes the repair of social relations and the development of consensus-building decision-making processes.

Answer 52

C. The National Comorbidity Survey (NCS) was a psychiatric epidemiologic survey conducted between 1990 and 1992, with a sample of about 8000. A decade later (2001–02), the National Comorbidity Study-Replication (NCS-R) was fielded, which aimed to obtain information on time trends in psychiatric disorders and provide estimates on the prevalence of psychiatric disorders according to DSM-IV criteria. Almost fifty percent (46.4%) of US adults over the age of 18 will meet criteria for a DSM-IV disorder during their lifetime. {https://www.sciencedirect.com/topics/medicine-and-dentistry/national-comorbidity-survey#:~:text=NCS%2DReplication%20Survey%20(NCS%2DR)&text=Lifetime%20prevalence%20estimates%20of%20DSM,and%20any%20disorder%2C%2046.4%25. And https://pubmed.ncbi.nlm.nih.gov/15939837/#:~:text=Conclusions%3A%20About%20half%20of%20Americans,usually%20in%20childhood%20or%20adolescence.}

Answer 53

A. The National Comorbidity Survey (NCS) was a psychiatric epidemiologic survey conducted between 1990 and 1992, with a sample of about 8000. A decade later (2001–02), the National Comorbidity Study-Replication (NCS-R) was fielded, which aimed to obtain information on time trends in psychiatric disorders and provide estimates on the prevalence of psychiatric disorders according to DSM-IV criteria. 28.8% will meet criteria for anxiety disorders during their lifetime. 20.8% will meet criteria for depression/mood disorders. 24.8% will meet criteria for impulse disorders. 14.6% will meet criteria for substance use disorders. Unfortunately, a major methodological problem with the NCS-R limits the conclusiveness and representativeness of alcohol and drug dependence results from this study. {https://www.sciencedirect.com/topics/medicine-and-dentistry/national-comorbidity-survey#:~:text=NCS%2DReplication%20Survey%20(NCS%2DR)&text=Lifetime%20prevalence%20estimates%20of%20DSM,and%20any%20disorder%2C%2046.4%25.}

Answer 54

B. Raising the minimum legal drinking age (MLDA) from 18 to 21 resulted in a median 15% decrease in fatal and non-fatal injury crashes (6-33% range) among those 18-20 years based on 4 studies. {Shults RA, Elder RW, Sleet DA, Nichols JL, Alao MO, Carande-Kulis VG, Zaza S, Sosin DM, Thompson RS; Task Force on Community Preventive Services. Reviews of evidence regarding interventions to reduce alcohol-impaired driving. Am J Prev Med. 2001 Nov;21(4 Suppl):66-88. doi: 10.1016/s0749-3797(01)00381-6. Erratum in: Am J Prev Med 2002 Jul;23(1):72. PMID: 11691562.}

Answer 55

C. According to the National Center for Statistics and Analysis, National Highway Traffic Safety Administration, approximately 40% of MVA’s in the US are alcohol-related. {2003 data?} Any fatal traffic crash involving a driver or motorcycle rider with a BAC of .08 g/dL or higher is considered to be an alcohol-impaired-driving crash. Fatalities occurring in those crashes are considered to be alcohol-impaired-driving fatalities, which accounted for 31 percent of overall fatalities in 2021. {https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813435}

Answer 56

D. According to the National Center for Health Statistics, the rate of suicide per 100,000 in 2007 was: 45.4 for white males ages 85 years and older; 22.2 for white males ages 20-24 years; 14.2 for black males ages 20-24 years; and 1.3 for white females ages 15-19. The rate of suicide per 100,000 in 2020 was: 37.4 for American Indian males 27 for white males 12.9 for black males 12.3 for Hispanic males 10.8 for American Indian females 10.3 for Asian/Pacific Islander males 6.9 for white females 3.8 for Asian/Pacific Islander females 2.9 for black females 2.8 for Hispanic females {https://www.nimh.nih.gov/health/statistics/suicide}

Answer 57

B. Males are more likely to commit suicide, but females make a greater number of suicide attempts. Males are more likely to use a firearm, compared to females who are more likely to use poison or overdose on drugs. 2020 suicides by method: (1) firearm—57.9% (male), 33% (female) (2) suffocation—26.7% (male), 29.1% (female) (3) poisoning—7.8% (male), 28.6% (female) {https://www.nimh.nih.gov/health/statistics/suicide}

Answer 58

B. According to the National Association of County and City Health Officers, 70% of local health departments fall under the jurisdiction of counties 19% fall under city or town jurisdiction 8% multi-county 3% other {https://www.naccho.org/uploads/downloadable-resources/Programs/Public-Health-Infrastructure/NACCHO_2019_Profile_final.pdf}

Answer 59

A. Based on data from the Center for Studying Health System Change, the percent of doctors in solo or two-physician practices declined from 40.7% to 32.5% during 1996-2005. The percent of doctors in 3-5-physician practices also declined during this time. Concurrently, there were small increases in number of physicians in 6-50-physician practices, physicians working for hospitals, and those joining medical school faculties.

Answer 60

A. Medicare Part A covers inpatient care in hospitals. A for admission. Part B is medical insurance which covers doctors’ services. B for basics. Part C comprises Medicare Advantage plans that are health care plans run by Medicare-approved private insurance companies. C for curated. Part D is the prescription drug benefit. D for drugs.

Answer 61

C. Prescription drugs grew from 6.9% of expenditures to 10.1% over this time period. In the same period, hospital care expenditures decreased slightly from 30.6% to 30.5%, physician and clinical services decreased from 21.1% to 20.3% and nursing home care decreased from 6.3% to 5.5%. Factors associated with the increase in expenditures for prescription drugs include more people with prescription drug coverage (especially Medicare recipients) and direct to consumer advertising used by pharmaceutical companies. 2021 health expenditures Retail prescription drugs (9% share) increased 7.8% vs. 3.7% in 2020 Physician and clinical services (20% share) increased 5.6% vs. 6.6% in 2020 Hospital care increased (31% share) 4.4% vs. 6.2% in 2020 Nursing care facilities (4% share) decreased 7.9% vs. 13.1 increase in 2020 {http://www.cms.gov/NationalHealthExpendData/}

Answer 62

A. Diagnostic Errors occur when a wrong action is taken or when there is failure to take an indicated action. Other common forms of medical error include: (1) Equipment Failure, which occurs when a specific device (such as a defibrillator or an IV pump) fails; (2) Translation Error, which occurs when the provider and patient do not speak the same language and important clinical information such as how to take a prescribed medication is not communicated properly; and (3) Misinterpretation of Medical Orders, which occurs when a physician order is acted upon incorrectly. {“To Err is Human,” www.nap.edu.readingroom}

Answer 63

A. Most studies looking at the association between body mass index and absenteeism at work have shown a consistent positive and statistically significant correlation between obesity and measures of absenteeism. Obesity was causally related to increased work absenteeism due to illness or injury: three additional workdays per year relative to normal weight, for an increase of 128 percent. {https://acoem.org/Publications/Press-Releases/Obesity-Has-Causal-Impact-on-Job-Absenteeism-and-Related-Costs} Hypertension, hypercholesterolemia and low physical activity level are all in the unknown category concerning their association with absenteeism at work.

Answer 64

B. Carpal tunnel syndrome (CTS) results from compression of the median nerve at the wrist. Symptoms include burning or tingling in the palm of the hand and fingers, often occurring at night because many people sleep with flexed wrists. Classic symptoms are usually described in the thumb-3rd fingers, the areas innervated by the median nerve. Muscular innervation of the median nerve encompasses the thenar muscles, particularly the abductor pollicis brevis, but not the hypothenar muscles (supplied by the ulnar nerve). Guyon’s canal, through which the ulnar nerve passes at the wrist, is relatively spacious, therefore the ulnar nerve is usually unaffected by pressure in the carpal tunnel, and has normal conduction velocity and latency in CTS cases.

Answer 65

D. Inhalation of crystalline silica can lead to chronic silicosis of the lung characterized by hyalinized nodules. Silica can be transported by macrophages via pulmonary lymphatics to the hilar nodes, that appear as “egg shell calcifications” on X-ray. Coal worker’s pneumonconiosis appears as fiborosis and small rounded opacities on X-ray without hilar node calcification. Asbestosis produces fibrotic changes in the lower lung zones and pleural plaques. Beryllium disease may produce non-caseating granulomatous lesions in the lungs similar to sarcoidosis; chest lymph nodes may be involved but are not calicified.

Answer 66

D. 75-85% of cases of low back pain (LBP) do not have a specific anatomic focus. Herniated disc should be suspected when accompanied by pain radiation, numbness, or weakness into the lower leg and foot; it occurs in about 5% of all LBP cases. Facet joint arthropathy is a radiological finding, but may be present in many asymptomatic individuals as well. The diagnosis of SI joint dysfunction is often made clinically, although pathological findings or discrete lesions are generally not seen.

Answer 67

C. Recommended exposure limits (RELs) of hazardous occupational exposures are established by the National Institute of Occupational Safety and Health, and do not have the force of law, although they may reflect current best-practices. RELs are provided to the Occupational Safety and Health Administration for consideration in establishing permissible exposure limits (PELs), which are the levels that are legally enforced by OSHA. The ACGIH develops Threshold Limit Values (TLV) and Biological Exposure Indices (BEI) which also reflect current scientific findings. The EPA sets standards for criteria air pollutants and maximum contaminant levels (MCLs) for drinking water.

Answer 68

A. Underground uranium mining is associated with emission of radon gas, a decay product of uranium. When inhaled radon gas decays, alpha radiation is emitted, increasing the risk of lung cancer. While radioactive sources may also emit beta particles, their role in carcinogenesis is minor, as they are too weak to penetrate to most nuclei. Asbestos, while also a lung carcinogen, was not present in these mines. Few if any miners received surveillance x-rays, and the dosages to the lung tissue are generally insufficient to cause lung cancer, in contrast to the direct effect of alpha radiation on the alveolar lining cells.

Answer 69

C. The researcher wants to compare means between two groups with sample sizes large enough (>30) for the central limit theorem to apply. Thus, a parametric test (for normal distributions) for two samples—the two-sample t-test—is the most appropriate. For comparing a continuous (weight) with an unpaired dichotomous variable (intervention group yes/no) use two sample t-test. The paired t-test is for comparing non-independent samples, such as data from matched pairs or before/after data of individuals. For comparing a continuous with a paired dichotomous variable use a paired t-test. ANOVA is used to compare the means of 3 or more groups. The Wilcoxon signed rank test is used to compare small samples of paired observations, and is considered the non-parametric counterpart of the paired t-test. For comparing an ordinal with a paired dichotomous variable use Wilcoxon matched-pairs signed ranks test. Tests specific for ordinal data are nonparametric, that is no assumptions are made about the distributional form of the data as is done in parametric tests. {Jeckel (2020), p. 150}

Answer 70

A. In cluster randomization, the population is divided into homogenous groups and a random sample of the groups are taken. In this question, the schools, rather than the individual students, are the unit of randomization, consistent with the definition of cluster randomization. Simple randomization uses a random number table or random number generator to allocate participants. Systematic randomization alternatively allocates one participant to intervention then to control and so on. Block randomization is simple or systematic randomization to create groups with equal numbers of participants. Stratified randomization assigns participants to strata based on baseline variables such as risks and then assigns each stratum randomly to intervention or control. {Jekel (2020), p. 189}

Answer 71

D. Regression toward the mean, also known as the statistical regression effect, is common among patients who were chosen to participate in a study because they had an extreme measurement on some variable. For many conditions, these patients are likely to have a measurement that is closer to average at a later time for reasons unrelated to the type or efficacy of the treatment they receive. In a study comparing treatment methods in two groups of patients, both with extreme measurements at the beginning of the study, randomization cannot eliminate the tendency to regress toward the mean. Allocation bias is a type of selection bias in which investigators influence the assignment of participants to one group or another. Intention to treat analyzes data in such a way that participants who dropped out of the study are analyzed as if they had remained in the original group. Controlling for variables of concern in analysis can identify confounding from differences in randomized groups. {Jekel (2020), pp. 188-190}

Answer 72

D. Standard deviation shows the variability of individual observations. The mean +/- 1.96 SD estimates the range in which 95% of individual observations would be expected to fall. Whether using a Z-score (known population standard deviation) or a t-score (standard deviation estimated from the sample), Z.975 or t.975 ≈ 2 for a sample size of 100. Using the equation for 95% confidence interval (written here in standard normal notation) of x ± Z.975 (SD/√n), the 95% confidence interval for LDL cholesterol in this problem is: 130 ± 2 (10/√100) = 130 ± 2 = (128, 132). {Jekel (2020), p. 134}

Answer 73

D. For comparing a continuous (distance) with another continuous (BMI) variable, linear regression with a Pearson correlation coefficient (r) is used. The value of r is 0 if there is no correlation and strong if +/-1. A negative correlation means that the value of y decreases as the value of x increases. The correlation coefficient, r, is the square root of R^2, but also indicates direction of the slope. From the graph, it is apparent that the slope is negative (BMI decreases with increasing distance from the fast food restaurant), so that r = - √r2 = -0.8. {Jekel (2020), pp. 151-152}

Answer 74

C. For comparing a continuous (distance) with another continuous (BMI) variable, linear regression with a Pearson correlation coefficient (r) is used. The value of r is 0 if there is no correlation and strong if +/-1. A negative correlation means that the value of y decreases as the value of x increases. The strength of association (R^2) represents the proportion of variation in y (outcome—BMI) explained by x (exposure—distance) and is an estimation of clinical importance. The R^2 reported in the question is 0.64, meaning that 64% of the variation in BMI is explained by distance. {Jekel (2020, p. 152}

Answer 75

A. For comparing a continuous (distance) with another continuous (BMI) variable, linear regression with a Pearson correlation coefficient (r) is used. The value of r is 0 if there is no correlation and strong if +/-1. A negative correlation means that the value of y decreases as the value of x increases. A correlation tells whether events co-occur. It does not give information about causality, which is implied in B-D. {Jekel (2020, p. 151}

Answer 76

B. Measures of central tendency locate observations on a measurement scale (similar to a street address for the variable). From visual inspection, this histogram of frequency distribution is clearly skewed (non-symmetric), so either the geometric mean or the median (not an answer choice in this question) would be appropriate measures of central tendency. The mean is the average value. It is more heavily influenced by extreme values, so will be found farther in the direction of the long tail in a skewed distribution. The arithmetic mean is the most commonly used type of mean and is often referred to simply as “the mean.” While the arithmetic mean is based on adding and dividing values, the geometric mean multiplies and finds the root of values. The geometric mean is not overly influenced by the very large values in a skewed distribution. The mode is also a measure of central tendency and represents the most commonly observed (or most frequent) value. It is of some clinical interest, but little statistical value. In a distribution skewed to the right as above, the mode will be farther to the left. The third measure of central tendency (not an answer choice in the question) is the median, which is the middle or the 50th percentile observation. It is seldom used to make complicated inferences because it does not lend itself to the development of advanced statistics. In a skewed distribution, the median is located between the arithmetic mean and the mode. Measures of dispersion suggest how widely the observations are spread out (similar to property lines for the variable). The standard deviation is a measure of dispersion based on the mean, not a measure of central tendency. {Jekel (2020, pp. 120, 123}

Answer 77

A. In a normal (Gaussian) distribution, mean = median = mode. The mean is more heavily influenced by extreme values, so will be found farther in the direction of the long tail in a skewed distribution. In a skewed distribution, the mode will be found in the body of the frequency distribution and the median will be between the mean and the mode. In a frequency distribution that is skewed to the right as above, the mode < median < mean (in the tail). In a frequency distribution that is skewed to the left, the mean (in the tail) < median < mode.

Answer 78

D. The samples for comparison are relatively small (<30) and are taken from non-normally distributed populations. Therefore, a non-parametric test should be used. Tests specific for ordinal data are nonparametric, that is no assumptions are made about the distributional form of the data as is done in parametric tests. The Wilcoxon rank sum test (similarly to the Mann-Whitney U-test) is used to compare small samples of unpaired observations. For comparing two samples, an ordinal (serum ferritin category) with a unpaired dichotomous (female yes/no) variable use Wilcoxon rank sum. The Kruskal Wallis test is the non-parametric equivalent of ANOVA, which is used to compare 3 or more groups. Parametric tests are used when the assumptions for a normal distribution are met, large sample size (>30) such that the central limit theorem applies. The paired t-test and two sample t-test are parametric tests. For comparing a continuous with a paired dichotomous variable use a paired t-test. The Wilcoxon signed rank test is considered the non-parametric counterpart of the paired t-test. For comparing a continuous with an unpaired dichotomous variable use two sample t-test. The Wilcoxon rank sum test and Man-Whitney U-test are considered non-parametric counterparts of the two sample t-test. {Jekel (2020), p. 150}

Answer 79

C. The null hypothesis for the F-test is that the mean change in SBP will be the same for all 4 groups. The ratio of the between-groups (variation between group means) to the within-groups (variation around the group means) variance is called F. The F-statistic calculated from the data is larger than the critical value for statistical significance, thus, the null hypothesis should be rejected. By definition of the ANOVA test, this is interpreted to indicate that at least one of the means is statistically significantly different than another. To determine which specific means are statistically significantly different than each other, pair-wise testing of the means must be done. {Jekel (2020), p. 176}

Answer 80

B. You are comparing the incidence (risk) of colds in subjects receiving zinc (a/n1 = 30/100 = 30%) with the incidence (risk) of colds in subjects not receiving zinc (c/n2 = 60/100 = 60%). Colds No Colds Zinc 30 70 100 Placebo 60 40 100 This comparison is the risk ratio ((a/n1)/(c/n2) = .3/.6 = .5). An RR of 0.5 indicates that colds are 50% less likely in those taking zinc compared with those taking placebo.

Answer 81

A. The Chi square test is a test of independence of two variables in a 2x2 contingency table. The Chi square test of significance is used for comparisons of proportions of two categorical (aka nominal) variables (predictor = zinc, yes/no and outcome = cold, yes/no). The logrank test is a test of significance for differences in survival. The test is often used to compare data in studies involving treatment and control groups and to test the null hypothesis that each group has the same death rate over time. The Kappa test ratio is a measure of intraobserver and interobserver agreement, which assesses the extent to which agreement exceeds that expected by chance. The two sample t-test is a parametric test for comparing a continuous with an unpaired dichotomous variable. {Jekel (2020), pp. 150, 167, 107}

Answer 82

D. The symptom severity data are ordinal and the sample sizes are small, thus a non-parametric test should be used. The data are also paired (before/after for each patient). The Wilcoxon signed rank test should be used as the non-parametric equivalent of the paired t-test. While the Wilcoxon signed-rank test is used to compare two paired samples, the Wilcoxon rank-sum test is used to compare two unpaired samples. ANOVA is a parametric test used for 3 or more groups. The two sample t-test is a parametric test for comparing a continuous with an unpaired dichotomous variable. {Jekel (2020), p. 150}

Answer 83

D. The hypothesis of the study is stated as an alternative hypothesis (HA) to the null hypothesis (H0). HA is RR_Statins < RR_NoStatins. H0 is the opposite of the stated hypothesis, i.e. that statins are associated with a higher risk of lymphoma. The null hypothesis must also include an equality. {Jekel (2020), p. 132}

Answer 84

C. In a longitudinal study, subjects are censored when they drop out of the trial or if they complete the trial without having the outcome of interest. Because the follow-up time of this trial is 1 year, the expected mean censoring time would be 52 weeks if all of the subjects stayed in the trial. The fact that the mean censoring time in the vaccine group was less than 52 weeks indicates that there were subjects who dropped out of the trial early in that group.

Answer 85

D. The Occupational Safety and Health Administration, part of the Department of Labor, is the federal agency responsible for enforcing regulations related to occupational hazards. The American Industrial Hygiene Association is a professional organization that publishes Threshold Limit Value recommendations. The Environmental Protection Agency enforces environmental rather than occupational regulations. The Environmental Protection Agency would have jurisdiction over exposures occurring outside of the industrial facility. The National Institute for Occupational Safety and Health is a research entity that is part of the Centers for Disease Control and Prevention

Answer 86

C. The audiogram demonstrates that this individual has experienced the most hearing loss at 4000 Hz in both ears (4000 Hz notch). This pattern of hearing loss is consistent with noise-induced hearing loss, which occurs through changes in the neural functioning of the inner ear. Conductive hearing loss or mixed conductive and sensorineural hearing loss would appear as decreased hearing across all frequencies. Congenital hearing loss would likewise often present as decreased hearing across all frequencies, rather than as hearing loss primarily in the upper frequencies and at 4000 Hz.

Answer 87

D. The employee is exhibiting signs of heat stroke, including confusion and lack of sweating. Heat stroke is a medical emergency requiring immediate cooling to reduce body temperature, along with supportive measures. The appropriate action in this situation where the employee is described as displaying potentially advanced symptoms of heat illness is for the employee to be evaluated in an emergency care setting. Options A through C would not be appropriate for an employee with symptoms of heat stroke.

Answer 88

C. Because our circadian rhythms operate on an internal “clock” that is slightly longer than 24 hours, employees tolerate forward shifting rotations much better than backward or random shift changes. A forward shifting rotation is characterized by changes in shift hours that have the employee working at progressively later hours (day to evening to night). Working longer shifts exacerbates fatigue. Starting shifts early is a form of backward rotation that can increase fatigue. Having more days off between shift changes allows time for circadian rhythms to adjust toward a more typical day/night cycle, which can make a return to evening and night work more fatiguing.

Answer 89

D. CIs are an alternative to p values (though preferable to many statisticians) and are not directly related to confounding. Matching assures that the comparisons have the same distribution of the confounder so it cannot influence the results. Multivariate adjustment (example, logistic regression) is a mathematical approach that controls for confounding by definition. Randomization is used to assure equal distribution across comparison groups through random distribution of known and unknown confounders.

Answer 90

C. Relative risk is incidence in exposed divided by incidence in unexposed or (b/a+b) / (d/c+d) = (20/100) / (1000/10,000) = 2.0

Answer 91

D. To calculate the risk ratio (RR) for death in women compared with men, the sex-specific death rates are needed. The problem simply states that there were a total of 24 deaths and does not specify how many of these deaths were women and how many were men. Therefore, the RR for death in 5 years following CABG for women compared with men cannot be estimated from the data given.

Answer 92

B. The positive predictive value is calculated as number of true positives divided by number of all test-positives or a/(a+b). Prevalence is calculated as all disease positives divided by the total population or (a+c)/(a+b+c+d). As prevalence (a+c) increases, a increases and positive predictive value increases (i.e., the more likely a test-positive will be a true positive). Different methods of treating diabetes would not have an effect on screening for diabetes. Sensitivity (a/a+c) and specificity (d/b+d) are intrinsic test qualities and do not change.

Answer 93

C. The cost of administering the questionnaire to 1000 people will be $2,000. If the prevalence of the disease is 5%, 50 people in the community will have the disease and 950 will not. Disease +. - Test. +. 45. 38. 83 - 5. 912 50. 950. 1000 Given a sensitivity (a/(a+c)) of the test of 90%, 45 of the 50 people who have the disease will test positive on the questionnaire. Given the specificity (d/(b+d)) of 96%, 912 of the 950 people without the disease will test negative and 38 will test positive (false positives). Thus a total of 45 + 38 = 83 people will test positive on the questionnaire and will go to the next stage of testing, the MRI, at a cost of $83,000. The total cost of the screening program is thus $2,000 (for questionnaires) + $83,000 (for MRIs) = $85,000.

Answer 94

C. The total number of person-years in the study is 1(100) + 2(200) + 3(150) + 4(100) + 5(50) = 1600 person-years. Thus the death rate is 120 deaths per 1,600 person years, which is equal to 75 per 1,000 person-years.

Answer 95

C. A lower false positive rate would mean fewer people without the disease would be considered to have the disease. Because people without the disease but considered to have the disease would survive longer, reducing their numbers in the disease cohort would tend to decrease the survival, not increase as is seen in this problem. Lead time bias leads to apparent increased survival by detecting cases earlier in their progression, without changing the overall duration of the progression. Length bias leads to apparent increased survival by detecting longer duration cases rather than shorter, more lethal cases. The true benefit of screening refers to earlier diagnosis leading to improved treatment that does increases actual survival time.

Answer 96

A. Because osteosarcoma is rare, you would need very large cohorts for the cross-sectional survey and the cohort study to obtain the desired number of 100 cases (100,000 people to find 1 case = 10,000,000 to find 100 cases). Thus the case-control study—wherein 100 cases are identified from the outset and controls are obtained at a 1:1 to approximately 1:4 or 1:5 ratio—would require orders of magnitude fewer subjects (200-600 subjects) and is thus much more efficient. A randomized controlled trial is not relevant to the problem as there is no intervention.

Answer 97

E. In 2019 the U.S. Preventive Services Task Force (USPSTF) recommended screening all patients 18–79 years of age at least once for hepatitis C with the anti-HCV antibody test. Detection of hepatitis C virus (HCV) RNA by polymerase chain reaction (PCR) testing provides evidence of active HCV infection, confirms the diagnosis, and is used in monitoring the antiviral response to therapy. Quantitative PCR is used to determine viral load. The CDC previously recommended screening for people born between 1945 and 1965, but that has been expanded. HCV is the most common chronic bloodborne pathogen in the United States and a leading cause of complications from chronic liver disease. Before the COVID pandemic, HCV infection was associated with more deaths than the top 60 other reportable infectious diseases combined, including HIV. The most important risk factor for HCV infection is past or current injection drug use. In the United States an estimated 4.1 million people have past or current HCV infection, based on a positive test for the anti-HCV antibody. Approximately 2.4 million persons with a positive antibody test have a current infection based on results of molecular assays for HCV RNA and would be potential candidates for treatment. Treatment results in very high levels of virus remission. Cases of acute HCV infection increased approximately 3.5-fold between 2010 and 2017. The increased incidence has mostly affected young white people who inject drugs, especially those living in rural areas. There has also been an increase in the number of women age 15–44 years with HCV infection. There is no recommended testing frequency for high-risk individuals at this time.

Answer 98

E. Not only are tobacco cessation treatments effective clinically, they are also cost-effective in comparison to treatments for other medical disorders (SOR A). Several analyses have found that the cost of treatment per patient who quits ranges from several hundred to a few thousand dollars. Insurance coverage of medications and counseling to stop smoking increases success rates (SOR A). Bupropion, varenicline, and five forms of nicotine replacement (gum, inhaler, lozenge, nasal spray, and patch) have all been shown to be effective in helping adults quit smoking (SOR A). For every 10 smokers who quit while taking a placebo nearly 30 could be expected to quit when taking varenicline as a single agent. Varenicline as a single agent has also been shown to help about 50% more people quit smoking compared to nicotine replacement therapy (NRT). Varenicline has been shown to be more effective than the nicotine patch (odds ratio [OR] 1.510), nicotine gum (OR 1.72), and other forms of NRT including inhalers, sprays, tablets, or lozenges (OR 1.42). However, varenicline was not shown to be more effective than combination NRT (OR 1.06). Combination NRT using a nicotine patch plus an additional form such as a lozenge also outperformed single NRT. A systematic review demonstrated that a combination of NRT and varenicline appears to have the highest quit rates. A meta-analysis of the bupropion and varenicline trials found no difference between the active drugs and placebo arms (risk ratio 1.06) with regard to neuropsychiatric events. Nortriptyline nearly doubles the chances of quitting but may have more side effects such as dry mouth. Unlike varenicline, neither nortriptyline nor bupropion was shown to enhance the effect of NRT compared with NRT alone. Telephone quit lines are also effective for tobacco cessation (SOR A). They reach a diverse population, and family physicians and other clinicians are encouraged to promote their use as supportive therapy when using pharmacologic approaches.

Answer 99

B. HPV is the most common sexually transmitted infection in the world and there is good evidence that most individuals who are sexually active will be exposed to HPV at some time. It is estimated that 20 million people in the United States are infected with this virus. HPV vaccine is highly immunogenic and efficacious, and is very well tolerated. The CDC’s Advisory Committee on Immunization Practices (ACIP) recommends routine administration of the HPV vaccine for both males and females at 11–12 years of age, so that they are vaccinated before becoming sexually active. The minimum age approved for the vaccine is 9 years. In addition, catch-up vaccination has been recommended for females ages 12–26 if they have not been previously vaccinated or if they have not completed the vaccine series (SOR A). The vaccine may also be given to those age 26–45 after a discussion of the benefits and shared decision-making, although the benefit is much lower in this age group. According to the ACIP, people in this age group who are not in a monogamous relationship and are sexually active should still be offered the vaccine, as well as those who are sexually active with a new partner. The recommended HPV series is two doses for those who start the vaccine series before the age of 15. The second dose should be given 6–12 months after the first dose. For patients who begin the vaccine series at age 15 or after, a three-dose schedule is recommended by the CDC, with the second dose given 1–2 months after the first dose and the third dose 6 months after the first dose. HPV types that cause most HPV cancers and genital warts have dropped 86% among teen girls. Among vaccinated women the percentage of cervical precancers caused by the HPV types most often linked to cervical cancer has dropped by 40%.

Answer 100

B. The U.S. Preventive Services Task Force (USPSTF) recommends screening mammography every 2 years beginning at age 40 for women at average risk of breast cancer (B recommendation). This includes people with a family history of breast cancer and people who have other risk factors, such as having dense breasts. Cancer screening guidelines for women with a history of breast augmentation are the same as for other women. The USPSTF recommends against teaching breast self-examination (D recommendation) and has found insufficient evidence to recommend for or against clinical breast examinations to screen asymptomatic women (I recommendation). Clinical trials have not found that mortality is improved in women screened with a clinical breast examination when done in concert with mammography. The patient should be provided with this information and the physician should ask about her preferences with regard to the clinical breast examination. The USPSTF also recommends that patients with a family or personal history of breast, ovarian, fallopian tube, or peritoneal cancer be screened with an instrument such as the Tyrer-Cuzick. Brief screening tools should also be used with patients from certain high-risk populations. Those with a positive or high-risk result should undergo genetic counseling for consideration of testing for BRCA gene mutations. Typical screening recommendations may not apply to patients at very high risk of breast cancer, such as those with a history of high-dose radiation therapy to their chest at a young age. Patients at very high risk are not usually enrolled in studies that establish population-based recommendations for screening, and they require individual decision-making. Patients with a history of a high-risk lesion on previous biopsies also require individualized recommendations for surveillance. The USPSTF has concluded that the evidence is insufficient to assess the benefits and harms of MRI screening for breast cancer in those with dense breast tissue and more research is needed in this area (I recommendation).

Answer 101

B. The Fagerström Test for Cigarette Dependence, formerly called the Fagerström Test for Nicotine Dependence, is available in both a long form and an abbreviated form. Use of this test can help a physician determine the intensity of a smoker’s addiction, and thereby help determine dosages for medications used to help smokers quit. The short form of the test asks only when the patient smokes the first cigarette of the day and how many cigarettes are smoked each day. These questions have been shown to be both valid and reliable. The long form asks about smoking at inappropriate places and times, including during illnesses, and about when cravings are strongest.

Answer 102

B. The Fagerström Test for Cigarette Dependence, formerly called the Fagerström Test for Nicotine Dependence, is available in both a long form and an abbreviated form. Use of this test can help a physician determine the intensity of a smoker’s addiction, and thereby help determine dosages for medications used to help smokers quit. The short form of the test asks only when the patient smokes the first cigarette of the day and how many cigarettes are smoked each day. These questions have been shown to be both valid and reliable. The long form asks about smoking at inappropriate places and times, including during illnesses, and about when cravings are strongest.

Answer 103

C. Although aerobic exercise has traditionally been emphasized for its health benefits, research increasingly suggests that complementary resistance training also has favorable effects on cardiovascular function, coronary risk factors, and physical and psychosocial well-being. The American Heart Association recommends the inclusion of resistance training for healthy persons of all ages, and for many patients with chronic diseases, including cardiovascular disease (SOR C). Programs that include a single set of 8–10 different exercises performed 2–3 days a week have been shown to be beneficial. Although a greater frequency of training is an option, the additional gain is usually small. While the number of exercises can be reduced, training the front and back of major muscle groups (e.g., chest/back, biceps/triceps) is recommended. A repetition range of 8–12 is recommended for healthy participants younger than 50–60 years of age. To reduce the risk for injury, 10–15 repetitions at a lower relative resistance is generally recommended for cardiac patients and healthy participants over 50–60 years of age. Higher-intensity efforts (fewer repetitions with heavier weights) increase the risk of musculoskeletal injury. The American College of Sports Medicine recommends that older adults perform the following each week: a minimum of 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity, and two or more nonconsecutive days of moderate-intensity strengthening activities, with 8–10 exercises involving the major muscle groups and 8–12 repetitions of each exercise.

Answer 104

C. Smoking history (at least 100 cigarettes in a lifetime) and male sex are the major risk factors for abdominal aortic aneurysm (AAA). The U.S. Preventive Services Task Force (USPSTF) recommends one-time screening for AAA by ultrasonography between the ages of 65 and 75 in men who have ever smoked (B recommendation). The USPSTF also recommends that clinicians selectively offer screening for AAA in men in this age group who have never smoked if indicated by the patient’s medical history, family history, other risk factors, or personal values (C recommendation). An important risk factor in addition to age is a first degree relative with AAA. Other risk factors include a history of other vascular aneurysms, coronary artery disease, cerebrovascular disease, atherosclerosis, hypercholesterolemia, obesity, or hypertension. The likelihood of finding an AAA large enough to benefit from surgery is greatest between the ages of 65 and 75. In patients older than 75 the likelihood of surviving surgery to repair an AAA is low enough to preclude screening. The benefit of screening for women in this age group is low due to the low number of AAA-related deaths in this population (SOR B). The USPSTF recommends against routine screening for AAA in women (D recommendation). The USPSTF does not make any recommendation regarding testing those less than 65 years old.

Answer 105

A. The American College of Obstetricians and Gynecologists, the American Academy of Family Physicians, and the CDC recommend influenza vaccine for all women who will be pregnant during influenza season. It has been shown to reduce the risk of influenza-associated acute respiratory infection in pregnant women by about one-half and reduces a pregnant woman’s risk of being hospitalized with influenza by an average of 40%. The CDC recommends use of injectable influenza vaccines, including inactivated influenza vaccines and recombinant influenza vaccines. The nasal spray vaccine, which is a live attenuated influenza vaccine, is not recommended during pregnancy. Influenza vaccine is also recommended for women who are breastfeeding (SOR A). Current CDC guidelines recommend oseltamivir as the preferred treatment for pregnant women with suspected influenza. People with egg allergies such as hives, but no previous reaction to influenza vaccine in the past, no longer need to be observed for an allergic reaction for 30 minutes after receiving influenza vaccine. Monitoring for 30 minutes may be done if this is the first time the patient has received influenza vaccine but is not mandatory according to the CDC. Any licensed and recommended influenza vaccine that is otherwise appropriate for the recipient’s age and health status may be used. Patients who report reactions to egg involving symptoms other than hives, such as angioedema, respiratory distress, lightheadedness, or recurrent emesis, or who required epinephrine or another emergency medical intervention, may also receive any licensed and recommended influenza vaccine that is otherwise appropriate for the recipient’s age and health status. If an egg-based vaccine is used, it should be administered in an inpatient or outpatient medical setting, including, but not necessarily limited to hospitals, clinics, health departments, and physician offices. Vaccine administration should be supervised by a health care provider who is able to recognize and manage severe allergic conditions. These precautions are not necessary if the recombinant or cell culture–based vaccines are used.

Answer 106

D. Obtaining a urinalysis is not recommended in asymptomatic individuals unless clinical signs such as elevated blood pressure warrant further investigation. Cardiac auscultation to detect murmurs is important to assess for any change in a heart murmur with a Valsalva type maneuver, which could indicate hypertrophic cardiomyopathy. Evaluation of femoral pulses can detect coarctation of the aorta. It is appropriate to perform hearing and vision screenings during a preparticipation evaluation.

Answer 107

D. Current evidence does not suggest that the use of electronic cigarettes (e-cigarettes, or vaping products) for tobacco cessation is effective in adolescents. Studies in adults have shown mixed results. In a meta-analysis of 29 articles, e-cigarettes led to modest cessation rates, with benefits including behavioral and sensory gratification. In other studies participants continued to use e-cigarettes to maintain their habit instead of quitting. A total of 22 toxic substances apart from nicotine were reported in the liquid used in vaping cartridges and in their emissions. Vitamin E acetate, an additive in some vaping products, especially those containing tetrahydrocannabinol, has been strongly linked to the development of e-cigarette or vaping product use–associated lung injury (EVALI), which causes cough, dyspnea, and often gastrointestinal symptoms. EVALI may cause severe alveolar damage, and individuals as young as 15 have died from it. Patients who vape should be asked about all substances they add to vaping products and be counseled to stop. The evidence is insufficient to support the claim that vaping causes less second-hand exposure than regular cigarettes. One study showed that passive exposure to e-cigarette aerosol increased serum levels of cotinine similar to those associated with passive exposure to conventional cigarette smoke. There is no evidence that gradually lowering the nicotine dose in vaping products attenuates nicotine withdrawal.

Answer 108

A. A Tdap booster is recommended during every pregnancy. It should be given at 27–36 weeks gestation if at all possible. This allows transmission of pertussis antibodies to the fetus before birth and will protect the infant for the first 2–3 months before primary immunizations take effect. If the mother received Tdap early in the pregnancy an additional dose is not required. Td vaccine does not provide protection against pertussis.

Answer 109

A. In 2011 the National Lung Screening Test (NLST) reported that screening with low-dose CT reduces mortality from lung cancer in high-risk patients. A 2013 systematic review of the evidence regarding lung cancer screening using low-dose CT concluded that screening may benefit individuals at high risk for lung cancer. The U.S. Preventive Services Task Force currently recommends annual screening for lung cancer with low-dose CT in adults age 50–80 who have a 20-pack-year smoking history and currently smoke or have quit within the past 15 years. They also recommend that screening be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery (B recommendation). Screening with sputum cytology or chest x-ray is not effective for lung cancer screening.

Answer 110

D. Regular aerobic exercise has been shown to reduce blood pressure in both normotensive and hypertensive individuals. Studies have shown a lowering of blood pressure even in the absence of weight loss. Regular aerobic exercise has been shown to reduce insulin resistance and, in conjunction with weight loss, has been shown to reduce the progression from prediabetes to type 2 diabetes. This patient is currently only slightly overweight and will not benefit significantly from weight loss alone. This patient’s cardiac risk score is 4.5%, which is below the 7.5% threshold recommended by the American College of Cardiology/American Heart Association guidelines for statin therapy. (A heart risk calculator can be found at http://www.cvriskcalculator.com/.) The U.S. Preventive Services Task Force, however, recommends that adults with no history of cardiovascular disease (CVD) use a low- to moderate-dose statin for the prevention of CVD events and mortality when they are age 40–75; have one or more CVD risk factors, such as dyslipidemia, diabetes mellitus, hypertension, or smoking; and have a calculated 10-year risk of a cardiovascular event of 10% or greater. Because of this patient’s cardiac risk score, he does not meet all three criteria.

Answer 111

C. Substance abuse is usually defined as problematic use of alcohol, illicit drugs, or tobacco. Substance abuse frequently goes unrecognized in the primary care setting, making recognition of its prevalence critical. An estimated 10% of persons age 12 or older in the United States have an illicit drug problem. The number of people who abuse alcohol is even higher, with 24.9% of those in this age group classified as binge drinkers and 6.5% classified as heavy alcohol users. Patients with substance abuse problems are more likely to develop medical problems and more likely to access care frequently, compared to the general population. Typical red flags in the history of patients with substance abuse problems include relationship difficulties, unexplained trauma, DUI, and an erratic occupational history. In addition, patients with mental health disorders have a higher prevalence of substance abuse, especially those with depression and personality disorders. The 2017 National Survey on Drug Use and Health provided a snapshot of the ongoing opioid epidemic and mental health across the country. The report found that 1 in 12 American adults (18.7 million) had a substance use disorder and that 1 in 5 (46.6 million) had a mental illness. More than 8.5 million were found to have both a substance use disorder and mental illness. In 2018 an update of the survey found that nearly 22 million people in the United States had a substance use disorder, with nearly 58 million people in the United States having either a substance use disorder or a mental health disorder. The National Institute on Drug Abuse website includes useful research, resources for clinical practice, and toolboxes (http://www.nida.nih.gov). The references cited also provide a wealth of information on substance use for many different drugs and segments of the population and should be utilized to obtain the most up-to-date statistics.

Answer 112

B. According to the 2017 American College of Cardiology/American Heart Association hypertension guidelines, limiting daily alcohol intake to 1–2 drinks in men and 1 drink in women has the least impact on lowering systolic blood pressure (SBP) among nonpharmacologic interventions in hypertensive individuals, with an anticipated reduction of 4 mm Hg in SBP. Adoption of the Dietary Approaches to Hypertension (DASH) diet is the most effective dietary intervention for reducing SBP, with an approximate average reduction of 11 mm Hg. The DASH diet is rich in fruits, vegetables, whole grains, and low-fat dairy products, with reduced amounts of saturated and total fat compared to the typical American diet. Weight loss is a core recommendation in overweight and obese individuals, with an expected drop in SBP of about 1 mm Hg per kg of weight loss. Engaging in regular aerobic exercise 90–150 minutes per week is also an effective intervention, leading to expected reductions of 5–8 mm Hg in SBP. Reduction of dietary sodium intake by at least 1000 mg daily (with an optimal goal of <1500 mg daily) would be expected to reduce SBP by 5–6 mm Hg.

Answer 113

B. Categories of alcohol use have been established by the National Institute on Alcohol Abuse and Alcoholism. Moderate drinking is defined as up to one standard drink per day in women and up to two per day in men. Heavy alcohol use includes high-volume drinking, defined as 14 or more standard drinks per week on average for males and 7 or more standard drinks for females, and high-quantity consumption, defined as consumption on any given day of 4 or more standard drinks for males and 3 or more standard drinks for females. Although patients with a heavy alcohol use pattern by definition may not have developed adverse consequences, this pattern places them at risk for such consequences. Alcohol abuse is a maladaptive pattern of drinking leading to clinically significant impairment or distress. Alcohol dependence is characterized by multiple symptoms, including tolerance, signs of withdrawal, and diminished control over drinking.

Answer 114

B. Female Hodgkin’s disease survivors treated with chest irradiation are at increased risk of developing breast cancer and surveillance should be started at 25 years of age (SOR C). Breast cancer patients should be counseled that intensive surveillance using laboratory and imaging tests does not improve overall survival or quality of life. However, monthly breast self-examination, annual mammography of preserved breast tissue, and a careful history and physical examination every 6 months for 5 years are recommended (SOR C). A Cochrane review, based on two randomized, controlled trials, found that less-intensive follow-up strategies based on periodic clinical examinations and annual mammography seem as effective as more-intense surveillance. Any positive findings on the history and physical examination would certainly warrant further investigation, however. Although expert opinion recommends frequent carcinoembryonic antigen (CEA) testing and CT scans for follow-up of colorectal cancer patients, there is insufficient evidence to support any optimal combination of tests or frequency of clinical follow-up. CEA testing and CT scans every 6 months versus at 1 and 3 years did not yield a clinically significant difference in 5-year mortality or cancer-specific mortality in a 2018 meta-analysis of patients with stage 2 or 3 colorectal cancer. Another meta-analysis from 2015 demonstrated that more-intensive follow-up was not associated with an improvement in cancer-specific survival nor with an increased detection of total tumor recurrences. A 2016 Cochrane review on this subject found no overall survival benefit for increased follow-up of patients after curative surgery for colorectal cancer. Even though more participants were treated with salvage surgery with curative intent in the intensive follow-up group, this was not associated with improved survival. Expert recommendations suggest that prostate cancer survivors should have annual digital rectal examinations, and that PSA levels should be monitored every 6 months for 5 years, and then annually (SOR C). Family physicians should be aware of survivorship care plans as tools to improve care coordination and outcomes for cancer survivors.

Answer 115

C. According to the CDC guidelines influenza vaccine should be administered before the end of October, but it can be given throughout the entire influenza season. It can also be given at regular health care visits before October if that is more convenient for the patient, and if there is a likelihood that the patient might not get the vaccine otherwise. Emphasis should be placed on vaccinating individuals prior to the start of influenza activity in the community (SOR A). When the vaccine is closely matched to the antigenic strains circulating in the population there are decreases in antibiotic use, hospitalization, absenteeism, and the use of health care resources in general (SOR B). Viral shedding studies within family units indicate that children with influenza shed the virus longer and have a greater potential to become infected, so vaccination of children for influenza is an important public health intervention to reduce community disease burden.

Answer 116

B. The U.S. Preventive Services Task Force (USPSTF) recommends screening for osteoporosis with bone measurement testing in women age 65 and older (B recommendation). In postmenopausal women younger than 65 the USPSTF recommends screening with bone measurement testing in those at increased risk for osteoporosis based on results from a formal risk assessment tool (B recommendation). Formal clinical risk assessment tools include the Simple Calculated Osteoporosis Risk Estimation (SCORE), the Osteoporosis Risk Assessment Instrument (ORAI), the Osteoporosis Index of Risk (OSIRIS), and the Osteoporosis Self-Assessment Tool (OST). The commonly used threshold to identify an increased risk for osteoporosis or osteoporotic fractures is 6 for SCORE, 9 for ORAI, <1 for OSIRIS, and <2 for OST. The FRAX tool uses the following factors to determine a risk percentage: Parent history of fracture Previous personal fracture Smoking status Glucocorticoid use Rheumatoid arthritis Secondary osteoporosis conditions Alcohol use Age, sex, weight, and height The FRAX tool was developed at the University of Sheffield and provides a country-specific, computerized algorithm that calculates the 10-year probability of hip fracture and major osteoporotic fracture. In women younger than 65 the USPSTF threshold for screening with bone measurement testing is a 10-year major osteoporotic fracture risk of 8.4%, which exceeds that of a 65-year-old white female without major risk factors. Some observational and modeling studies have suggested screening intervals based on age, baseline bone mineral density, and calculation of the estimated time until the patient develops osteoporosis. However, limited evidence from two good-quality studies found no benefit from repeating bone measurement testing 4–8 years after initial screening.

Answer 117

D. MDMA, flunitrazepam, GHB, and ketamine are among the drugs used by teens and young adults at nightclubs, bars, raves, or trance parties. Raves and trance parties are generally nightlong dances, often held in warehouses. Many who attend these dances use club drugs in an effort to enhance the experience. MDMA is a synthetic psychoactive drug that is chemically similar to the stimulant methamphetamine and the hallucinogen mescaline. Street names for MDMA include ecstasy, XTC, and hug drug. It is taken as a pill. Results from the 2018 National Survey on Drug Use and Health showed that 7% of people over the age of 12 had used MDMA at some time during their life and 1% had used it in the past year. MDMA users might feel very alert or energetic at first. At raves they can dance for hours at a time. They may also experience distortions in time and other changes in perception. Some, however, can become anxious and agitated. Sweating or chills may occur, and MDMA users may feel faint or dizzy. MDMA can interfere with the body’s temperature regulation, which can cause dangerous hyperthermia. Other effects on the body include muscle tension, clenching of teeth, nausea, blurred vision, fainting, and chills or sweating. MDMA increases heart rate and blood pressure and can cause confusion, depression, sleep problems, intense fear, and anxiety. In regular abusers some of these side effects can last for days or weeks after taking MDMA. GHB, flunitrazepam, and ketamine have been referred to as date rape drugs, since they have been used to facilitate sexual assault. These drugs can be easily added to flavored drinks without the victim’s knowledge. Symptoms of GHB intoxication include relaxation, drowsiness, vision problems, nausea/vomiting, headache, loss of consciousness, loss of reflexes, seizures, coma, and death. Flunitrazepam (“roofies”) can cause sleepiness, a sensation of intoxication, visual and gastrointestinal disturbances, urinary retention, and loss of memory about the timespan when the person was under the drug’s effects. Ketamine, which can also be snorted or smoked, is associated with a loss of time and identity, feeling out of control, a dream-like sensation, numbness, and increased heart rate and blood pressure.

Answer 118

C. On average most adults need 7–9 hours of sleep each night, although the normal range is 5–10 hours. Teenagers need an average of 9 hours of sleep each night, and infants need about 16 hours a day (SOR B). Like their younger counterparts, the elderly need 7–9 hours of sleep each night. However, sleep disorders increase with age, and the elderly are much more likely to have sleep problems, including insomnia and a lack of deep sleep (SOR C). Sleeping less than 7 hours per night on a regular basis is associated with adverse health outcomes, including weight gain and obesity, diabetes mellitus, hypertension, heart disease and stroke, depression, and an increased risk of death. Other effects include impaired immune function, increased pain, impaired performance, increased errors, and a greater risk of accidents. Exercise is important for sleeping well. However, patients should be advised to exercise several hours before going to bed to avoid the stimulating effect of exercise. Other recommendations include maintaining a regular sleep schedule including bedtime and wake-up time, avoiding caffeine and alcohol intake 4–6 hours before bedtime, and performing relaxing activities before bed (SOR C). Watching television and using computers or cell phones before bedtime is not recommended because exposure to bright light sources can interfere with sleep initiation. Use of these devices is particularly not recommended in the bedroom.

Answer 119

A. The recombinant herpes zoster vaccine (Shingrix) is a recombinant subunit vaccine that combines a lyophilized varicella zoster virus glycoprotein E (gE) antigen and an adjuvant system. It does not contain a live virus and is administered in two doses of 0.5 mL each, with the second dose given 2–6 months after the initial dose. It has been shown to be more than 90% effective in preventing herpes zoster and postherpetic neuralgia. Its protective effect remains at 85% for at least 4 years after administration, unlike the previous herpes zoster vaccine (Zostavax), which contains a live attenuated varicella virus and only reduces the risk of herpes zoster by 51% and the risk of postherpetic neuralgia by 67%. The recombinant vaccine is indicated for people over the age of 50, whereas the live attenuated vaccine was recommended for people over the age of 60. The recombinant vaccine is recommended for patients who have had shingles in the past, as well as those who received the live attenuated vaccine in the past. When the older vaccine was available the CDC recommended that patients wait at least 8 weeks after receiving the live attenuated vaccine before getting the recombinant vaccine. There is no specific amount of time a patient who has had herpes zoster must wait before receiving the recombinant vaccine, but it should not be administered during an acute episode of zoster. When vaccinating adults age 50 years and older, there is no need to screen for a history of varicella infection or to conduct laboratory testing for serologic evidence of prior varicella infection. Testing is often a barrier to herpes zoster vaccination, and false negatives are common. Worldwide, more than 99% of adults age 50 years and older have been exposed to varicella zoster virus.

Answer 120

B. The U.S. Preventive Services Task Force (USPSTF) recommends screening for both gonorrhea and Chlamydia in sexually active women 24 years of age and younger (B recommendation). The USPSTF has found insufficient evidence for screening nonpregnant asymptomatic adults for thyroid dysfunction (I recommendation). Although the USPSTF recommends abdominal aortic aneurysm (AAA) screening by ultrasonography in men 65–75 years of age who have ever smoked, it found that current evidence is insufficient to assess the balance of benefits and harms of screening for AAA in women 65–75 years of age who have ever smoked (I recommendation). It is important to screen all children for developmental delays, especially those who are at a higher risk for developmental problems due to preterm birth, low birth weight, or having a sibling or parent with autism spectrum disorder (ASD). The USPSTF has noted the need for more research around autism screening. However, the CDC recommends that all children be screened specifically for ASD with a validated tool during regular well child visits at 18 and 24 months of age. The American Academy of Pediatrics recommends screening at 18 months with a second screen at 24 months because of the increased likelihood of false-positives at 18 months. Universal screening at an earlier age is not as accurate with the current tools available in primary care. A number of tests are available to screen for ASD in children younger than 30 months. The most commonly studied tool is the Modified Checklist for Autism in Toddlers (M-CHAT). Additional specialized screening might be needed if a child is at high risk for ASD, such as children with a sibling with ASD, or if symptoms are present.

Answer 121

B. Formal screening instruments such as the CAGE questionnaire, the Alcohol Use Disorders Identification Test (AUDIT), and the self-administered Michigan Alcoholism Screening Test (MAST) are the most effective method for screening for alcohol disorders in primary care. Although the CAGE questionnaire can identify patients with alcohol abuse and dependence, AUDIT is more effective for detecting hazardous or harmful drinking, with a sensitivity of 57%–97% and a specificity of 78%–96%, and is recommended by the U.S. Preventive Services Task Force. The MAST is 25 questions and may be more challenging to complete in a busy practice. The AUDIT is 10 questions and can be completed quite easily. The AUDIT includes questions about the quantity and frequency of alcohol use, as well as binge drinking, dependence symptoms, and alcohol-related problems. Its strength lies in its ability to identify people who may not be dependent. Research shows that the AUDIT may be useful when screening women and minorities. This screening tool also has shown promising results when tested in adolescents and young adults but it is less accurate in older patients. Biologic markers, such as aspartate aminotransferase, mean corpuscular volume, and γ-glutamyl transferase, do not work well as screening methods for alcohol problems in primary care.

Answer 122

D. According to the CDC’s Advisory Committee on Immunization Practices, HPV vaccination is recommended for all women <26 years of age, regardless of risk (SOR A). Ideally, the full vaccination series should be administered before potential exposure to HPV through sexual activity. Women who are sexually active should still be vaccinated, however, including those with a history of genital warts, abnormal Papanicolaou (Pap) smears, or positive HPV DNA tests. If the first dose of vaccine is given before the patient’s 15th birthday a two-dose schedule should be followed, with the second dose given 6–12 months after the first dose. The minimum interval is 5 months between the first and second dose. If the second dose is administered after a shorter interval, a third dose should be administered a minimum of 5 months after the first dose and a minimum of 12 weeks after the second dose. A series of three doses is recommended if the vaccine is initiated on or after the patient’s 15th birthday. The second dose should be administered 1–2 months after the first dose, and the third dose should be administered 6 months after the first dose. Vaccination is not routinely recommended for those over the age of 26. However, some adults age 27–45 who did not get adequately vaccinated when they were younger may decide to get the HPV vaccine after a discussion with their physician. HPV vaccination of people in this age range provides less benefit, as more of them have been already exposed to HPV. The FDA has approved a supplemental application for a recombinant 9-valent HPV vaccine and expanded the approved use of the vaccine to include women and men age 27–45.

Answer 123

B. Aspirin use may result in small to moderate harms, including gastrointestinal bleeding, which is more common in men, and hemorrhagic stroke, which is more common in those with a low BMI and Asian ethnic groups. Decisions about the use of low-dose aspirin therapy in primary prevention should take into account the patient’s overall risk for cardiovascular disease (CVD), colorectal cancer, and gastrointestinal bleeding. The 2019 American College of Cardiology/American Heart Association guideline for the primary prevention of cardiovascular disease recommends aspirin for adults age 40–70 who have an increased risk for CVD and no significant bleeding risk. The guideline also states that the use of aspirin for primary prevention in adults >70 years of age is potentially harmful. In the patient described in this scenario aspirin may increase the risk of bleeding. In 2016 the U.S. Preventive Services Task Force (USPSTF) changed its former A recommendation rating to a B recommendation for initiating low-dose aspirin use for the primary prevention of CVD and colorectal cancer in adults age 50–59 years who have a 10% or greater 10-year CVD risk, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years. The USPSTF made a C recommendation for adults age 60–69 years with a 10% or greater 10-year CVD risk. The recommendation states that the decision to initiate low-dose aspirin use should be an individual one. Patients who are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose aspirin daily for at least 10 years are more likely to benefit. Those who place a higher value on the potential benefits than the potential harms may choose to initiate low-dose aspirin.

Answer 124

A. Vitamin E supplementation appears to have a beneficial effect on progression of macular degeneration. It has not been proven to prevent Alzheimer’s dementia or mild cognitive impairment. Although vitamin E supplementation has not shown any benefit for prevention of cardiovascular disease in the general population, clinical trial data from the HOPE (Heart Outcomes Prevention Evaluation), ICARE (Israel Cardiovascular Events Reduction with Vitamin E), and Women’s Health Study clinical trial data has shown that in individuals with diabetes mellitus and the Hp2-2 genotype, vitamin E supplementation is associated with an approximately 35% reduction in cardiovascular disease. A meta-analysis from 2014 showed that vitamin E is safe in dosages up to 800 IU daily.

Answer 125

A. β-Carotene has been found in clinical trials with smokers to be related to increased rates of lung cancer and overall mortality. Furthermore, in 2003 and again in 2014 the U.S. Preventive Services Task Force specifically recommended against the use of β-carotene for chemoprevention of cancer for all adults (D recommendation). The evidence for vitamins A and C, and for multivitamins with folic acid, is insufficient to recommend for or against their use for prevention of cancer or cardiovascular disease (I recommendation).

Answer 126

C. Medical therapy for osteoarthritis should begin with full-strength acetaminophen and topical therapy, then proceed to NSAIDs and selectively to tramadol and other opioids. NSAIDs and opioids may reduce pain and improve function but have significant potential harms (SOR A). Based on meta-analyses of randomized, controlled trials physicians should perform laboratory screening for and eradicate Helicobacter pylori before initiating long-term NSAID therapy in NSAID-naive patients to reduce the risk of peptic ulcer disease (SOR A). Because of that finding the American College of Gastroenterology recommends testing for H. pylori infection before initiating long-term NSAID therapy, and offering eradication therapy to those with positive results (SOR A). Physicians should also screen for and eradicate H. pylori before initiating long-term NSAID therapy in patients with a history of peptic ulcers (SOR B). Treatment with standard dose H2-blockers is not effective for preventing peptic ulcers related to long-term NSAID use. Low-dose tramadol would not be recommended for this patient if other nonopioid medications provide relief. Establishing a baseline hemoglobin level is not necessary before starting NSAID treatment.

Answer 127

C. Cocaine and amphetamines (such as methamphetamine) are the most commonly abused stimulants. Detoxification involves interventions targeted at managing the acute intoxication, as well as the withdrawal period. It is the first step for patients who wish to become abstinent or who are in mandatory abstinence programs. In contrast, treatment or rehabilitation is the provision of ongoing services with the goal of promoting recovery. Family physicians are often called on to assist in detoxification in both outpatient and inpatient settings. In addition to detoxification the physician must address comorbid psychiatric illness and general medical disease. Comprehensive psychiatric management is the cornerstone of substance abuse treatment (SOR A) and will usually necessitate referral. Treatment programs should also integrate psychosocial aspects of care in a comprehensive treatment strategy. The symptoms of withdrawal from methamphetamine differ from those of alcohol, opioids, or sedatives. Common symptoms include fatigue, anxiety, irritability, depression, poor concentration, hypersomnia, psychomotor retardation, increased appetite, drug craving, and paranoia. Acamprosate is used for the management of alcohol dependence and is not indicated for stimulant addiction. Buprenorphine is approved for opioid dependence and has been used in some studies for stimulant addiction. In these studies it was more beneficial than methadone. There is limited evidence that some medications may be helpful in amphetamine dependence and abuse. An international study suggests using risperidone, aripiprazole, topiramate, and buprenorphine in certain situations. Haloperidol and risperidone reduced psychosis. Riluzole, a drug approved for treatment of amyotrophic lateral sclerosis (ALS), reduced craving, withdrawal, and depression compared with placebo. In a systematic review from 2020, the most consistent positive findings were demonstrated with stimulant agonist treatment (dexamphetamine and methylphenidate), naltrexone, and topiramate. Less consistent benefits have been shown with the antidepressants bupropion and mirtazapine. A commonly overlooked, and possibly lethal, component of stimulant withdrawal is profound dysphoria, involving negative thoughts and feelings and depressed mood. This may lead to suicidal ideation and attempts. The depressed affect and dysphoria associated with stimulant withdrawal are more profound and often longer lasting for patients who abuse methamphetamines. Thus, these patients warrant careful monitoring and treatment for depression and suicidality. Patients who are withdrawing from stimulants, including methamphetamines, often report headaches. However, persistent headaches may be due to intracerebral, subarachnoid, or subdural bleeding, and must be evaluated appropriately.

Answer 128

D. Pediatric obesity has become epidemic. Measures to prevent this condition should be shared with parents as early as possible. For infants, major recommendations to reduce the risk of obesity include breastfeeding (SOR A), avoiding television and computer screen time (SOR C), avoiding premature introduction of solid foods (SOR C), avoiding high-calorie beverages with low nutritional value (SOR C), and educating parents to be role models of healthy lifestyles (SOR C). Breastfeeding after the age of 12 months has been associated with a 47% reduction in obesity. Cow’s milk and fruit juice can be introduced at 12 months of age. Providing 100% fruit juice can be an important component of fruit intake in children who may not be able to access fresh fruits and eliminating them may cause nutritional deficiencies. It is important to only use 100% juice and to not exceed 4–6 oz daily for children 1–6 years of age. When consumed within the Dietary Guidelines for Americans recommendations, 100% fruit juice is not associated with overweight/obesity or childhood dental caries and does not compromise fiber intake. While there have been concerns in the past about low-fat diets and their effect on brain development, low-fat or fat-free milk is appropriate at this age, especially if there are concerns about obesity or a family history of cardiovascular disease (SOR A). Evidence does not support restricting flavored milk products to reduce the prevalence of obesity.

Answer 129

D. There are many reproductive problems related to smoking, including conception delay and both primary and secondary infertility; an increased risk of ectopic pregnancy and spontaneous abortion; an increased risk of abruption, preterm rupture of membranes, placenta previa, and premature delivery; and increased perinatal morbidity and mortality, including stillbirth, low birth weight, and SIDS-related deaths. The 2001 Surgeon General’s Report on women and smoking makes it clear that stopping smoking during pregnancy reduces and sometimes eliminates many of these consequences. Small for gestational age (SGA) infants are a dose-dependent outcome of maternal smoking, with an odds ratio (OR) of 2.11 when women smoke throughout pregnancy. Risks for prematurity (OR 1.15) and fetal death (OR 1.15) are also increased. The risk of having an SGA infant is avoided if smoking is reduced, but the risks for prematurity and increased fetal death are not. In 2014 the U.S. Surgeon General issued a new report on the health consequences of smoking that noted that the evidence was strong enough to infer a causal link between maternal smoking and orofacial clefts. This was still true when the Surgeon General issued a report on smoking cessation in 2020. No link could be inferred, however, between smoking and other congenital defects, including clubfoot, gastroschisis, and atrial septal defects. There is no evidence that maternal smoking leads to increased rates of childhood attention-deficit/hyperactivity disorder.

Answer 130

D. Erectile dysfunction (ED) is common, affecting an estimated 30 million men in the United States, and becomes more common with advancing age. The Health Professionals Follow-up Study reported moderate to severe ED in 12% of men younger than 59, 22% of men ages 60–69, and 30% of men older than 69. It was previously thought that the majority of cases of ED were caused by psychogenic factors such as family or occupational stress. However, evidence suggests that approximately 80% of ED is due to organic disease, which can be divided into hormonal, vasculogenic, and neurogenic causes. Vasculogenic etiologies are the most common, with arterial or “inflow” disorders accounting for more problems than venous disorders. The patient should be advised that their ED is a risk factor for underlying cardiovascular disease and that further evaluation may be appropriate. It is important to remember, however, that even though the primary etiology of ED is most often organic, psychological factors frequently coexist and play a role in the dysfunction. Many medications can cause or contribute to ED. It is estimated that as many as 25% of ED cases are due to medication side effects. This highlights the crucial role of the primary care physician in reviewing medication lists and modifying treatment regimens as part of addressing ED. Common offenders include antihistamines, antihypertensives and diuretics such as hydrochlorothiazide and spironolactone, psychoactive medications including SSRIs, and anti-epilepsy medications. It is not clear whether low amounts of alcohol cause erectile dysfunction.

Answer 131

C. Ovarian cancer is the fifth leading cause of cancer death among women in the United States. Risk factors associated with ovarian cancer include a positive family history and having the BRCA1 or BRCA2 gene mutation. A first or second degree relative with ovarian cancer increases the risk by about threefold. The use of oral contraceptives during the reproductive years, and pregnancy, especially after age 35, reduce the risk of ovarian cancer, but postmenopausal estrogen use may increase the risk. The U.S. Preventive Services Task Force does not currently recommend screening for ovarian cancer, as it is likely to have a relatively low yield (D recommendation). Almost all women with a positive screening test for CA-125 will not have ovarian cancer. In women at average risk, the positive predictive value of an abnormal CA-125 is approximately 2%, so 98% of women with positive test results will not have ovarian cancer. There are no current recommendations for ovarian cancer screening by either transvaginal ultrasonography or pelvic examination.

Answer 132

D. Drug use is one of the most common causes of preventable injuries, disability, and death. Data from 2018 showed that an estimated 12% of U.S. residents 18 years or older reported current unhealthy drug use. Unhealthy drug use was reported by 24% of adults age 18–25, 10% of older adults, and 8% of adolescents age 12–17. The U.S. Preventive Services Task Force (USPSTF) now recommends screening by asking questions about unhealthy drug use in adults age 18 years or older. Screening with written or verbal questions should be implemented when services for accurate diagnosis, effective treatment, and appropriate care can be offered in the practice or referred. The USPSTF does not recommend drug testing as a form of screening. The USPSTF states that there is currently insufficient evidence to assess the balance of benefits and harms of broad-based screening of adolescents. The data on counseling adolescents on drug use is mixed. Some smaller trials show some benefit from brief intervention for low-risk drug use such as cannabis and alcohol. Other studies fail to demonstrate a consistent benefit and can be difficult to interpret due to the complexity of meta-analyses and comparisons. The USPSTF does not make any recommendations on the timing or setting of screening. Screening is appropriate at any visit at clinics where care or referral for unhealthy drug use can occur. Practices may consider brief tools such as the National Institute on Drug Abuse (NIDA) Quick Screen, which asks four questions about use of alcohol, tobacco, and illegal drugs, along with nonmedical use of prescription drugs, in the past year. Longer tools like the eight-item Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), which assess risks associated with unhealthy drug use or comorbid conditions, may reveal information signaling the need for prompt diagnostic assessment. Another assessment is the Tobacco, Alcohol, Prescription medication, and other Substance use (TAPS) tool, which may be useful when clinicians are concerned about misuse of prescription medications.

Answer 133

D. Numerous sources have suggested that prevention is the best way to combat the epidemic of obesity. Being obese in childhood increases the risk for obesity in adulthood. Thus, it is currently recommended that physicians screen children annually for risk factors for being overweight. Risk factors for overweight and obesity include low or high birth weights, factors related to social determinants of health such as low socioeconomic levels, poor eating and sleeping habits, and >2 hours per day of sedentary activity such as watching television or playing computer games. Other factors such as a change in BMI >3–4 kg/m2 per year and depression are also associated with obesity. Adequate sleep has been found to be related to maintaining a healthy weight. All preschool children should get 10–12 hours of nighttime sleep with a nap during the day. Most preteens should sleep 10–12 hours per night. Parents should also be instructed on the 5-2-1-0 recommendation, which provides easily understood guidelines for prevention of childhood obesity. This recommendation says that children should have 5 servings of fruits and vegetables daily, no more than 2 hours of screen time daily, 1 hour of physical activity daily, and 0 sugary drinks daily. The BMI value by itself is not as meaningful when assessing children because normal values are based on age. For example, a 10-year-old male with a BMI of 23 kg/m2 would be considered obese, whereas a 15-year-old male with the same BMI would not. A BMI above the 85th percentile is considered overweight. The American Academy of Pediatrics recommends screening for obesity starting at age 2, with interventions for any child with a BMI between the 85th and 94th percentile for age and sex. The U.S. Preventive Services Task Force recommends screening for obesity starting at age 6, with referral to intensive therapy (more than 26 contact hours) for children with a BMI greater than the 95th percentile for age and sex.

Answer 134

D. The American Diabetes Association (ADA) recommends screening all people over the age of 45 for diabetes mellitus every 3 years with a fasting plasma glucose level, a 2-hour oral glucose tolerance test, or a hemoglobin A1c (HbA1c). It is important to remember when using HbA1c for screening that hemolytic anemias and acute blood loss can falsely lower HbA1c, whereas prior splenectomy and aplastic anemias, which increase erythrocyte age, can falsely elevate HbA1c. Hemoglobinopathies and hemoglobin variants can result in variable changes in HbA1c level and may be more prevalent among certain racial and ethnic groups. When used for diagnostic purposes the HbA1c test should be performed using a method that is certified by the NGSP (http://www.ngsp.org) and standardized or traceable to the Diabetes Control and Complications Trial (DCCT) reference assay. Screening should be performed before age 45 for any individual with a BMI ≥25 kg/m2 (≥23 kg/m2 in Asian-Americans) who has any of the following additional risk factors: physical inactivity a low HDL-cholesterol level (<35 mg/dL) or a high triglyceride level (>250 mg/dL) a first degree relative with diabetes mellitus polycystic ovary syndrome or other insulin-resistance conditions such as acanthosis nigricans high-risk ethnicity, including African-American, Latino, Native American, Asian-American, and Pacific Islander a previous glucose tolerance test with elevated results or a hemoglobin A1c >5.7% a history of cardiovascular disease a blood pressure ≥140/90 mm Hg or receiving treatment for hypertension The ADA also recommends that women who have been diagnosed with gestational diabetes should receive lifelong screening every 3 years. U.S. Preventive Services Task Force (USPSTF) recommendations are slightly different. They recommend screening all adults 40–70 years of age who are overweight or obese (B recommendation). The USPSTF recommends that earlier screening or using a lower BMI cutoff should be considered for some patients, including those who have a family history of diabetes, have a history of gestational diabetes or polycystic ovary syndrome, or are members of certain racial/ethnic groups (African-American, Native American or Alaskan Native, Asian-American, Hispanic, or Native Hawaiian or Pacific Islander). If screening results are normal, repeat testing is recommended at a minimum of 3-year intervals.

Answer 135

A. According to the National Institute of Alcohol Abuse and Alcoholism, a standard alcoholic drink is equivalent to 12 oz of beer; 8.5 oz of malt liquor; 5 oz of table wine; 3.5 oz of fortified or dessert wine; 2.5 oz of cordial, liqueur, or aperitif; and 1.5 oz of spirits (one jigger of gin, vodka, whiskey, etc.) (SOR C).

Answer 136

A. Daily intake of at least 100 g of polyphenol-rich dark chocolate has been found to be associated with a 3-mm reduction in systolic blood pressure and improved formation of vasodilative nitric oxide. In addition, another study found a statistically significant reduction in blood pressure with the consumption of 40 g of soybean protein. Licorice has been associated with hypertension in humans. The Dietary Approaches to Stop Hypertension (DASH) diet, which has been shown to reduce blood pressure, emphasizes fruits, vegetables, and low-fat dairy products, and a reduced intake of dietary cholesterol, saturated and total fat, sweets, and sugar-containing beverages. Cheese generally has a high amount of sodium. For example, a relatively small (30 g) serving of American cheese contains approximately 400 mg of sodium and the same amount of cheddar cheese contains approximately 200 mg of sodium.

Answer 137

E. A systematic review of 53 randomized trials, including 9140 patients, found that oral naltrexone increased abstinence rates (number needed to treat [NNT]=20) and decreased heavy drinking (NNT=12) (SOR A). There is some evidence that disulfiram reduces drinking days (SOR B), but little evidence for promoting abstinence. Adherence is a key predictor of the success of disulfiram. In addition, supervised use of disulfiram seems to have better outcomes. A systematic review generally showed that pharmacologic treatment was more efficacious than placebo in terms of controlling drinking, achieving abstinence, and reducing drinking days, alcohol consumption, and craving. Naltrexone would be indicated in a patient with normal liver enzyme levels, increased cravings, and possible binge drinking. Acamprosate is contraindicated in patients with stage 4 kidney disease (glomerular filtration rate <30 mL/min/1.73 m2) and disulfiram is contraindicated in patients with coronary artery disease. Disulfiram is also contraindicated in patients with a history of psychosis, because it can increase dopamine levels and induce psychotic episodes in these patients. Gabapentin may also be used to treat alcohol withdrawal, and there is some evidence that it can reduce cravings. Lorazepam would not be indicated for long-term therapy. Although there are studies showing some benefit to using SSRIs in patients with concomitant depression and alcohol use disorder, an SSRI would not be indicated in a patient with a low Patient Health Questionnaire–9 (PHQ-9) score.

Answer 138

A. A history of breast cancer in any male relative justifies referral for BRCA testing (B recommendation). According to the U.S. Preventive Services Task Force (USPSTF), patients should generally NOT be referred for BRCA counseling or screening because of breast cancer in a female first degree relative unless the diagnosis was made before the age of 55 (B recommendation). One exception is Ashkenazi Jewish women, who are at increased risk for BRCA mutations and should be considered for testing if there is a family history of breast cancer in one first degree relative (B recommendation). Bilateral breast cancer in a first degree relative also justifies referral for BRCA testing (B recommendation). BRCA mutations increase the risk for both breast and ovarian cancer before age 70 (35%–84% and 10%–50%, respectively). A family history of both types of cancer in first or second degree relatives significantly increases the risk of having a BRCA mutation, and screening is recommended (B recommendation). Validated tools evaluated by the USPSTF include the Ontario Family History Assessment Tool, Manchester Scoring System, Referral Screening Tool, Pedigree Assessment Tool, 7-Question Family History Screening Tool, International Breast Cancer Intervention Study instrument (Tyrer-Cuzick), and brief versions of BRCAPRO. General breast cancer risk assessment models, such as the National Cancer Institute Breast Cancer Risk Assessment Tool (Gail Model), are not designed to identify BRCA-related cancer risk and should not be used for this purpose. Patients should be offered genetic counseling to thoroughly discuss ramifications of testing before ordering BRCA testing.

Answer 139

A. There is substantial evidence that a weight loss of 10 kg (22 lb) confers numerous health benefits, including a reduction of up to 20 mm Hg in systolic blood pressure and a concomitant reduction in the need for antihypertensive medication (SOR A). LDL-cholesterol levels have been estimated to decrease by 1% for every kg lost (SOR C). In a Finnish study of 522 middle-aged men with impaired glucose tolerance, intensive individualized instruction on weight reduction, food intake, and increasing physical activity resulted in a 58% reduction in the incidence of diabetes mellitus compared to the control group. In this study, weight reduction of as little as 5%–10% was found to lower the risk of developing diabetes. In the Diabetes Prevention Program the number needed to treat to prevent one case of incident diabetes was 6.9 for the intensive lifestyle intervention compared to 13.9 for metformin, although the efficacy of metformin approached that of the intensive lifestyle intervention in younger subjects and in those with a higher BMI or fasting plasma glucose level at baseline. The median delay in diabetes onset was estimated at 11 years for the intensive lifestyle intervention and 3 years for metformin. The American College of Sports Medicine and the American Diabetes Association Position paper on prevention of diabetes notes a meta-analysis of 10 cohort studies that found a risk reduction for type 2 diabetes of 0.70 (0.58–0.84) for walking on a regular basis (typically briskly for ≥2.5 hours per week).

Answer 140

D. Physical activity levels of children are important to health and for avoiding obesity across the lifespan. While it may not be possible to determine to what extent activity levels are taught rather than inherent, it is clear that physical activity of children in relation to their peers is largely determined by 3 years of age. There is evidence that in children 8–10 years of age, television watching and activity levels are inversely correlated, as are activity levels and obesity. When children are induced to significantly reduce television watching, even below the recommended maximum of 2 hours per day, activity increases and BMI decreases. In adolescence, both boys and girls tend to reduce physical activity levels, but this is much more pronounced in girls. Girls may therefore need additional support and encouragement to maintain health-enhancing physical activity.

Answer 141

D. Bupropion is an atypical antidepressant which is effective for tobacco cessation and is thought to inhibit dopamine and norepinephrine reuptake. Bupropion sustained-release formulations are approved for smoking cessation. A Cochrane review of antidepressants for smoking cessation found that both bupropion and nortriptyline are effective, while other tricyclic antidepressants, SSRIs, and anxiolytics are ineffective. Adding bupropion to varenicline does not lead to increased rates of smoking cessation. There is no evidence that bupropion or varenicline increases the risk of coronary artery disease (SOR A). The 2008 Public Health Service tobacco cessation guideline revision confirmed the utility of combining bupropion with nicotine replacement therapy (SOR A). Bupropion is combined with either the nicotine patch or an intermittent-dose formulation of nicotine replacement, or with both the patch and an intermittent dose formulation for patients with significant breakthrough cravings. Bupropion is contraindicated in patients with a present or past history of seizure disorders, a previous history of significant head injury, or anorexia nervosa or bulimia, as well as those taking another medication that lowers the seizure threshold.

Answer 142

D. Family physicians can play an important role in the prevention and treatment of sexually transmitted infections (STIs). The focus of primary STI prevention should be on helping patients change sexual behaviors that put them at risk for infection. Physicians should regularly obtain adequate sexual histories from their patients and address risk reduction. STI counseling should be client centered, meaning it should include risk reduction messages that are specific to and relevant to the individual patient, as well as education on the specific actions that can reduce risk. Condoms are a common choice for reducing STI risk, as well as preventing pregnancy. The physician can help ensure that the patient is educated about the selection and use of condoms. There are two types of non-latex condoms on the market. One is made of polyurethane or another synthetic material, and is equivalent to latex condoms in efficacy for prevention of STI transmission and pregnancy. These can be used by people who have latex allergies. Natural membrane condoms (also called lambskin condoms) are made from the cecum of lambs and have pores or openings in the material up to 1500 nm in diameter. This represents 10 times the diameter of the human immunodeficiency virus (HIV) and 25 times the diameter of the hepatitis B virus. Thus, natural material condoms are NOT recommended for the prevention of STD transmission. However, this type of condom has an efficacy similar to that of latex for the prevention of pregnancy. Limited evidence shows that correct and consistent use of the male condom may decrease the risk of transmission of the herpes simplex virus type 2 (HSV-2) from an infected male to his uninfected female partner. However, subgroup analysis revealed no significant difference in transmission of HSV-2 from an infected woman to her uninfected male partner if a condom was used. There are no systematic reviews or randomized, controlled trials on female condoms and HSV-2 transmission. Male latex condoms are also effective in preventing transmission of HIV and decrease transmission of Chlamydia, gonorrhea, and trichomoniasis. They may also reduce the risk that a woman will develop pelvic inflammatory disease, and they may reduce the risk of HPV-associated disease. Inconsistent or incorrect application of the condom is by far the most common reason for failure to prevent STI transmission or pregnancy. In the United States, the average rate of breakage during sexual intercourse and withdrawal is only 2/100. Condoms are subject to random sampling and testing by the FDA, and each latex condom manufactured in this country is tested electronically by the manufacturer for holes.

Answer 143

D. Likelihood ratios indicate the probability that a patient has a disease with a positive test. Unlike positive and negative predictive values, likelihood ratios do not change with the prevalence of the disease in a given population. A likelihood ratio of 1 indicates that a positive test does not change the likelihood of the disease, and the higher the likelihood ratio is above 1, the more likely it is that a test rules in a disease. The positive likelihood ratio is equal to the sensitivity of the test divided by one minus the specificity. In the example given in this question, dividing 0.20 by 1.0 – 0.96 yields a positive likelihood ratio of 5.0. The negative likelihood ratio is calculated by one minus the sensitivity divided by the specificity.

Answer 144

D. The 2004 U.S. Surgeon General’s Report expanded the list of smoking-related cancers, noting that the evidence either suggested or was strong enough to infer causal relationships between smoking and cancers of the lung, larynx, oral cavity, pharynx, esophagus, stomach, liver, pancreas, colon and rectum, uterine cervix, kidney, and bladder, as well as other sites. Smoking was also causally linked to adult myeloid leukemia. In 2014 the Surgeon General released a report marking 50 years since the first Surgeon General’s report on smoking. This report also examined links between smoking and cancer, and discussed causal links to lung cancer, liver cancer, and colorectal cancer, as well as evidence suggesting a link between breast cancer and smoking. The 2014 report also notes that smoking does not cause prostate cancer. The evidence did show that smoking increases the risk of dying in patients with cancer, including those with breast or prostate cancer. The risk of cancer from smoking shows a clear relationship to both the number of cigarettes smoked each day and the duration of smoking; the earlier one begins to smoke, the higher the risk. While the increased risk of lung cancer due to smoking starts to decline within about 5 years among persons who stop smoking, the residual risk may persist for several decades. Stopping smoking before middle age greatly decreases the risk of lung cancer, and cessation sharply reduces the risk of laryngeal cancer within 10 years. The risk of bladder cancer, on the other hand, persists much longer after cessation (level of evidence 2 for all findings).

Answer 145

A. Advanced age is the strongest risk factor for the development of prostate cancer. Prostate cancer is found most often in men over the age of 50, with 80% of those with prostate cancer being over age 65. In the United States, Black men have a significantly higher incidence of prostate cancer than white men (217.5 versus 134.5 cases per 100,000 men), and more than twice the prostate cancer mortality rate (56.1 versus 23.4 deaths per 100,000 men). The National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program has also reported a link between high dietary fat intake and the development of prostate cancer. Men with a family history of prostate cancer are at increased risk for prostate cancer, and for death from the disease. The U.S. Preventive Services Task Force (USPSTF) updated its recommendation in 2018 and now recommends that for men age 55–69 the decision to undergo periodic prostate-specific antigen (PSA) screening for prostate cancer should be an individual one (C recommendation). They recommend against PSA screening for men age 70 and older (D recommendation). The USPSTF concluded that PSA screening may reduce prostate cancer mortality risk, but it is also associated with false-positive results, biopsy complications, and overdiagnosis. In addition, the USPSTF concluded that compared with conservative approaches, active treatments for prostate cancer detected by screening have unclear effects on long-term survival and are associated with sexual and urinary difficulties. In a study of men with normal PSA levels, a digital rectal examination identified an additional 2% of men who were found to have clinical prostate cancer based on further analysis. However, there is very little evidence that screening rectal examinations in asymptomatic men above the age of 70 leads to a reduction in prostate cancer deaths.

Answer 146

E. Pharmacologic agents can be an effective part of a weight loss plan. However, patients should be counseled regarding realistic expectations and possible risks. The average weight loss is approximately 5 kg (11 lb) for many of the agents and much of the weight that is lost while taking these agents is regained after the drug is stopped (SOR A). Use of these agents in the absence of lifestyle interventions can actually decrease a person’s ability to lose weight in the future (SOR B). In a meta-analysis liraglutide was associated with 63% of patients losing at least 5 kg. Phentermine/topiramate has the highest success rate, with 75% of patients losing at least 5 kg. Orlistat may be associated with a high incidence of side effects, especially diarrhea associated with consumption of a high-fat meal. Liraglutide may be used for weight loss in patients without diabetes. Even high dosages of up to 3 mg daily can be prescribed safely if the patient can tolerate the dose.

Answer 147

B. Patients with a previous fasting glucose level >100 mg/dL should be retested for diabetes mellitus using either a validated hemoglobin A1c test or a repeat fasting glucose level. A 2-hour glucose challenge would require a separate visit and fasting status and would potentially place an additional burden on the patient to make an additional visit to the clinic and wait the 2 hours required for testing. A repeat lipid panel is not necessary for this patient, as his cardiac risk is only 3.5% based on the American College of Cardiology/American Heart Association risk stratification.

Answer 148

E. To lose weight, a person must create a caloric deficit either by increased activity or decreased caloric intake. A caloric deficit of at least 3500 kcal should theoretically produce a weight loss of 1 lb, so a caloric deficit of 500 kcal daily is required to produce a 1-lb weight loss in 1 week (SOR A). There are numerous diets published, including low-calorie, very-low-calorie, low-fat, very-low-fat, and low-carbohydrate among others, but long-term compliance is problematic. Typically, one-third to one-half of weight loss is not maintained by diet alone. In one study, Paleo diets resulted in less weight loss compared with intermittent fasting and a Mediterranean diet. Very-low-calorie diets (400–500 kcal daily) may increase rates of early weight loss, but weight loss at 1 year is similar to that from a low-calorie diet (800–1500 kcal daily) (SOR A). Low-fat diets, with fat accounting for 10%–19% of calories, do not produce weight loss without a decrease in total caloric intake (SOR A). The Mediterranean diet and behavior modification, such as the use of meal-replacement shakes, has been proven to improve long-term weight loss. Intermittent fasting may produce results similar to pharmacologic means, resulting in a loss of about 9 lb.

Answer 149

B. Statistics show that at least one-third of adults age 65 and older fall annually. Falls are the leading cause of nonfatal injuries and place the victims at increased risk for subsequent premature death. As the population ages, preventing this common cause of morbidity is of growing importance. Studies have found numerous modifiable risk factors related to falls. A combination of vision assessment and exercise was associated with a reduced incidence of falls. Tai chi in particular appears to reduce the risks of falling (level of evidence 1). Neither karate nor stretching has been shown to help seniors prevent falls. Environmental assessments by themselves have yielded mixed results in fall prevention in otherwise average-risk persons. Trials of different vitamin D formulations (with or without calcium), dosing schedules, and varying baseline fall risk show mixed results at 9–36 months of follow-up. A single trial of annual high-dose cholecalciferol (500,000 IU) showed an increase in fall risk. Increasing calcium intake by itself has not been shown to reduce the incidence of falls.

Answer 150

D. The U.S. Preventive Services Task Force (USPSTF) recommends initiation of pre-exposure prophylaxis (PrEP) for HIV in the following populations: Men who have sex with men, are sexually active, and are in a sexual relationship with a partner who is HIV positive, OR who use condoms inconsistently during receptive or insertive anal sex, OR who have had syphilis, gonorrhea, or a Chlamydia infection within the past 6 months Heterosexually active women and men who are in a sexual relationship with a partner who is HIV positive, OR who use condoms inconsistently during sex with a partner whose HIV status is unknown and who is at high risk, such as a person who injects drugs or a man who has sex with men and women, OR who have had syphilis or gonorrhea within the past 6 months Persons who inject drugs and share drug-injection equipment, OR who are at risk for sexual acquisition of HIV (see above) Two medications have been approved for use as PrEP by the FDA: emtricitabine/tenofovir disoproxil, 200 mg/300 mg once daily, and emtricitabine/tenofovir alafenamide, 200 mg/25 mg once daily. Studies have shown that daily PrEP reduces the risk of HIV from sex by about 99%. In people who inject drugs, daily PrEP reduces the risk of HIV by at least 74%. PrEP is much less effective if it is not taken consistently. Recommending abstinence alone is usually not sufficient. Using condoms 100% of the time will reduce transmission of HIV by 80%, and will also reduce transmission of other sexually transmitted infections (STIs). Since this patient had an STI 4 months ago, PrEP therapy is indicated. Testing for herpes-virus antibodies is not indicated and another test of cure for Chlamydia infection is not needed. Hepatitis B status should be determined before initiation of PrEP, but this patient has recently been tested so testing is not necessary at this time. It is not necessary to determine the patient’s hepatitis C status before starting PrEP, and given the patient’s recent test it would not be indicated for other reasons at this time.

Answer 151

B. Ten-year cardiac risk assessment calculators have not been validated for persons under the age of 40. However, since much of the process of atherosclerosis begins in young adulthood, the 2018 American Heart Association guidelines recommend screening for hyperlipidemia starting at age 20 with either a fasting or nonfasting lipid profile and a lifetime risk assessment (SOR B). If the serum triglyceride level is >400 mg/dL on a nonfasting specimen a fasting test is recommended. Patients under the age of 40 with severe primary hypercholesterolemia (LDL-cholesterol level ≥190 mg/dL) are considered to be at high risk for atherosclerotic cardiovascular disease and familial hypercholesterolemia, and maximally tolerated statin therapy is recommended. Assessing for risk-enhancing factors is also recommended. These include a family history of early coronary artery disease (before age 55 in males or 65 in females), metabolic syndrome, chronic kidney disease, chronic inflammatory diseases (systemic lupus erythematosus, psoriasis, and others), a history of preeclampsia, or South Asian ancestry. These factors should be taken into account if the patient’s LDL-cholesterol level is 160–189 mg/dL. Statins are not currently recommended for patients with these risk factors who are under the age of 40, and more research is needed to define the benefits of statin treatment in this population.

Answer 152

B. Available screening tests for dementia, such as the Mini-Mental State Examination (MMSE), the Functional Activities Questionnaire (FAQ), the Montreal Cognitive Assessment (MoCA), and others, have good sensitivity but only fair specificity for diagnosing dementia and other neurocognitive disorders. The positive and negative predictive value of these instruments will vary depending on the practice setting and the prevalence of dementia in the patient population (SOR A). In populations with a high prevalence of dementia, such as patients over the age of 85, positive predictive values can be >50%. In populations with a lower prevalence, such as unselected patients age 65–74, the positive predictive value may be closer to 20%. The sensitivity and specificity of these tools is typically lower for mild cognitive impairment than for dementia. The MoCA may be a more sensitive screening tool than the MMSE for mild cognitive impairment. In 2011 Medicare began covering screening for cognitive impairment as part of the annual wellness visit. In 2018 the American Academy of Neurology published recommendations to perform screening with a validated instrument and not rely on subjective assessment of memory to diagnose mild cognitive impairment. If patients are diagnosed with mild cognitive impairment a search for reversible causes should be undertaken because a subset of patients will show improvement in function over time with appropriate intervention and with exercise. Patients should be assessed for functional impairment before being given a diagnosis of dementia. The U.S. Preventive Services Task Force has concluded that the current evidence is insufficient to assess the balance of benefits and harms of screening for cognitive impairment in older adults.

Answer 153

C. A meta-analysis of 79 clinical trials involving diet plus sibutramine, orlistat, and phentermine, as well as several other drugs not approved for weight reduction, showed a placebo-adjusted overall average weight loss of <5 kg (11 lb) at 1 year. Long-term weight loss maintenance is very challenging using pharmacologic methods only, so there are no studies to demonstrate long-term morbidity and mortality benefits. Although they are not FDA approved for diabetes prevention, several medications have been shown to decrease incident diabetes mellitus. This includes several medications used for the treatment of diabetes, such as metformin, α-glucosidase inhibitors, GLP-1 inhibitors, and thiazolidinediones, as well as the weight loss drug orlistat. The relative risk of diarrhea and flatulence was >3.1 with orlistat compared to placebo. Since phentermine is a sympathomimetic amine, palpitations, tachycardia, and elevated blood pressure can be expected as side effects, but the drug is not contraindicated unless the patient has moderate to severe hypertension (SOR A). Topiramate inhibits carbonic anhydrase activity and has been linked to hypokalemia, kidney stone formation, and hyperchloremic, nonanion gap metabolic acidosis. For patients started on phentermine/topiramate a basic metabolic panel that includes bicarbonate, creatinine, potassium, and glucose is recommended at baseline and periodically during treatment. Exercise and diet changes with pharmacotherapy will produce the greatest changes in weight.

Answer 154

D. The U.S. Preventive Services Task Force (USPSTF) recommends screening all sexually active nonpregnant women age 24 or younger, as well as older women who are at increased risk for chlamydial infection, regardless of age (B recommendation). Screening for chlamydial infection is also recommended for all pregnant women regardless of age, and positive results should be followed up by a test-of-cure culture in 3–4 weeks. Routine screening for chlamydial infection is not recommended in nonpregnant women age 25 and older (C recommendation). The USPSTF found that there is currently insufficient evidence to support screening for chlamydial infection in heterosexual men with no risk factors. However, the CDC recommends screening for men who do have risk factors, such as men who have sex with men, men who currently reside in a correctional facility, or men who have been treated at STD clinics.

Answer 155

A. The appropriate measure of association In a case control study is the odds ratio. From the data, we can create a 2 X 2 table. To make the calculations easy, we use 100 cases and 100 controls: The odds ratio is calculated as (a*d) / (b*c) = (20*85) / (15*80) = 1.4.

Answer 156

C. Power is equal to 1-beta, where the beta error is the probability of not rejecting a null hypothesis when it is actually false. In this case, the power is 50%, so the beta error is 1-0.5 = 0.5 or 50%. This means you have a high probability of not finding a significant association that actually exists in this study.

Answer 157

C. For obesity, the RR adjusted for physical activity is substantially lower than the unadjusted RR. Thus, physical activity is a confounder of the association between obesity and Disease X; by definition, a confounder is also associated with the outcome, and therefore option C is NOT true. The unadjusted RR for obesity of 2.4 is equal to a 140% increase in risk compared with normal weight (2.4 – 1.0 = 1.4 or 140%) and the RR adjusted for physical activity is equal to a 70% increase (1.7-1.0 = 0.7 or 70%); thus option B is correct. Given that the 95% confidence intervals do not include the null value for RR or 1.0, both the unadjusted and adjusted RR’s for obesity are statistically significant at p<0.05, making options A and D both true.

Answer 158

C. The RR for selenium is in opposite directions for men and women, making it clear that, by definition, gender is an effect modifier in the trial. The 99% confidence intervals of the RRs of both genders do not include the null value of 1.0 and therefore the effect of selenium is statistically significant in both men and women at p<0.01 and making it unlikely that the differences between them are due to chance.

Answer 159

A. A double-blind study is one in which all subjects and all investigators assessing the outcomes are not aware of any subject’s intervention status.

Answer 160

D. The study was large, reducing the likelihood that the effect was due to chance, and the subjects were randomly assigned to treatment and placebo groups, reducing the likelihood of confounding. These factors, along with the multicenter nature of the trial, also make it unlikely that the subjects are not representative of subjects with recurrent stroke. Therefore, it is likely that the results of the trial are true — that telmisartan does not reduce the risk of recurrent stroke.

Answer 161

C. From the data, we can create a 2 X 2 table. To make the calculations easy, we use 1000 total subjects, with Disease X occurring in 100 (10% prevalence): Sensitivity is calculated in disease + subjects (first column); if sensitivity is 90% then 90% of those with Disease X, or 90/100, will test positive and 10% (10/100) will test negative. Specificity is calculated in disease – subjects (2nd column) (n=900); if specificity is 90%, then 90% (810/900) of those who are disease negative will test negative and 10% (90/900) will test positive. Positive predictive value is defined as the proportion of those testing positive who actually have the disease (a/a+b). In this case, a total of 180 subjects tested positive, 90 (50%) of which actually have the disease.

Answer 162

A. Utilization management is a cost-containment strategy that limis health care expenditures by limiting reimbursement. It includes preadmission certification, concurrent (during admission) review, case management and disease management. It is linked to quality improvement, but quality improvement is not its primary objective.

Answer 163

C. According to the US Census Bureau, approximately 60% of Americans received health insurance coverage from their employer in 2009 and was still 54.5% in 2022. It should be noted that persons could be covered by more than 1 type of health insurance in a year, so a proportion of these Americans may also have been covered by a governmental insurance program as well. {https://www.census.gov/library/publications/2023/demo/p60-281.html}

Answer 164

A. There are two general types of entitlement programs of which these government health care programs are a part: 1. Public assistance, which is means-tested, meaning benefits are based on financial need and limited to low-income recipients. Medicaid is one such program; or 2. Social insurance, where the claim to benefits are non-means tested, but rather are based on age (Medicare), disability (Social Security Disability Insurance), or previous employment (Veteran's Administration).

Answer 165

C. In a staff-model HMO, providers are employed by the HMO and typically receive salary.

Answer 166

A. The requirement for informed consent to participate in a study is based on the ethical principle of "autonomy" or "respect for persons," which regards individuals as autonomous agents who are capable of deliberating about personal goals and acting on that deliberation. Beneficence refers to the provider doing what's in the best interest of the patient. Non-maleficence is the principle of "first do no harm." Justice concerns fairness in deciding who gets treatment.

Answer 167

C. The National Practitioner Data Bank was established by the Health Care Quality Improvement Act of 1986 to facilitate a comprehensive review of professional credentials. It is adminsterd by the Bureau of Health Professions within HRSA.

Answer 168

C. The three categories for measuring health care quality proposed by Donabedian included 1. structure, referring to the attributes of the settings in which care occurs; 2. process, which denotes what is actually done in giving and receiving care; and 3. outcome measures, which are used to caputre the effect of an intervention on health status, specific clinical findings, or patients' perceptions of care. In this case, counting the number of facilities with the capability of providing adequate care is a structure measure. Determining how many patients actually receive this service would be a process measure and determining percentage of patients who have their disease controlled by this process would be an outcome measure.

Answer 169

A. Medicare Part A provides payment for hospital inpatient services. This payment is based on Diagnosis Related Groupings (DRGs) which provide a schedule for payments for services before they are delivered, i.e. prospective payments.

Answer 170

C. In a Network model, the HMO contracts with more than 1 multispecialty group to provide all covered services for the enrolled population of the HMO. When only 1 group is contracted, it is called a Group-model HMO.

Answer 171

B. The price is what the consumer is asked to pay for a good or service. Cost is the actual monetary value of the resources consumed in producing a good or service. Reimbursement is what the payor provides for the service.

Answer 172

C. Actuarial data show that male smokers die an average of 13 years earlier than their non-smoking counterparts; for females, the rate is about 15 years earlier for smokers compared with non-smokers.

Answer 173

D. Vertebral compression fractures often occur with minimal stress, such as coughing, lifting, or bending. The vertebrae of the middle and lower thoracic spine and upper lumbar spine are involved most frequently.

Answer 174

D. The most significant risk factor for COPD is exposure to tobacco smoke, primarily one's own smoking, but also large amounts of second-hand smoke. Long-term exposure to occupational dusts and chemicals and air pollution are also major risk factors for the disease. Recurrent pneumonia is a complication of COPD, not a risk factor.

Answer 175

C. According to the American Heart Association and the National Heart, Lung and Blood Institute, all of the criteria listed are correct except triglycerides where the cut-off is 150 mg/dL, not 300 mg/dL.

Answer 176

C. In cost-benefit analyses, all costs and benefits are valued in a common metric, most often monetary. In cost-effectiveness analyses, costs are valued in monetary units and effectiveness is measured in natural units of health improvment, e.g. years of added life, percent disease prevented, etc. In cost-utility analyses costs are monetary and the outcome, utility, includes the value placed on the levels of health status as determined by preference of individuals or society.

Answer 177

D. A sensitivity analysis is used to determine how results would change if the assumptions or parameters used in the primary analysis were varied. It helps determine how "robust" the result is in the face of changes in these inputs. In a cost-benefit analysis, the monetary value of the costs and the benefits are compared. A decision analysis uses the probability and costs of outcome events to project the average cost per patient for alternatives being compared. A cost-minimization analysis determines the least costly intervention to accomplish a given result.

Answer 178

C. The discount over 1 year at 4% is calculated as $1,000 * 1/1.04. For 3 years it would be $1,000 * 1/1.04 * 1/1.04 * 1/1.04 or $1,000 * 1/1.043, which = $889.

Answer 179

A. The Health Insurance Portability and Accountability Act, initially passed in 1996, limits restrictions on benefits for pre-existing conditions under Title I, and sets national standards for electronic health data exchange and provides for security and privacy of health data under Title II. It does not cover informed consent requirements for research studies.

Answer 180

D. The Physician-Patient relationship is a fiduciary relationship or one built on mutual trust. It has been defined by U.S. courts as "a consensual relationship in which the patient knowingly seeks the physician's assistance and in which the physician knowingly accepts the person as a patient." Formation of this relationship has a relatively low threshold; it does not require an appointment, claim, or payment. Once the physician-patient has been established, it continues until it is ended by the consent of the parties or revoked by the dismissal of the physician, or until the physician's services are no longer needed. Without proper notice of withdrawal, affording the patient ample opportunity to seek alternative care, the physician's termination of services to the patient could be held to be an abandonment, subjecting the physician to the charge of negligence and liability to the patient for any damages proximately caused by such negligence.

Answer 181

A. The Consolidated Omnibus Budget Reconciliation Act (COBRA) gives workers and their families who lose their health benefits the right to choose to continue group health benefits provided by their group health plan for limited periods of time under certain circumstances such as voluntary or involuntary job loss, reduction in the hours worked, transition between jobs, death, divorce, and other life events. Qualified individuals may be required to pay the entire premium for coverage up to 102 percent of the cost to the plan. COBRA generally requires that group health plans sponsored by employers with 20 or more employees in the prior year offer employees and their families the opportunity for a temporary extension of health coverage in certain instances where coverage under the plan would otherwise end. The Employee Retirement Income Security Act of 1974 (ERISA) is a federal law that sets minimum standards for most voluntarily established pension and health plans in private industry to provide protection for individuals in these plans. The Hill-Burton Act is a federal program which requires obligated facilities (health care facilities including hospitals that have used federal money for facility reconstruction or modernization) to provide free or low cost health care services to people living in the facility’s area who cannot afford to pay for the services and are not covered by a third-party insurer or a governmental program such as Medicaid or Medicare. The Omnibus Reconciliation Act of 1993 did not have health care provisions.

Answer 182

C. The Comprehensive Energy Response, Compensation and Liability Act (CERCLA) of 1980 is legislation that established a “Superfund” for clean-up of abandoned or active sites contaminated by hazardous waste. CERCLA imposes joint and several liability, with joint meaning that more than one defendant is liable to the plaintiff and several liability meaning the plaintiff may choose to sue only one of the defendants and recover the entire amount claimed. Retrospective liability refers to application of the law to events preceding its enactment. The Resource Conservation and Recovery Act which preceded CERCLA in 1976 gave the EPA authority to control hazardous substances from “cradle to grave” and included regulation of underground storage tanks.

Answer 183

A. The Clean Water Act established a permitting system through which discharge of pollutants into water would be regulated. It had the goal of making surface waters “swimmable or fishable.” The Safe Drinking Water Act of 1974 established standards for public water systems and also provided protection of ground water.

Answer 184

D. To be covered by the American with Disabilities Act, a person must meet the definition of disability, not be merely regard as one. Disabilities must be accommodated even if they are corrected with devices such as glasses or hearing aids.

Answer 185

D. Randomization serves to reduce confounding. The process required by randomized controlled trial designs make such studies less generalizable. Control groups often realize some benefit; by itself randomization does not preclude this. The issue of chance is answered by statistical analysis, not study design.

Answer 186

D. Randomization serves to reduce confounding. The process required by randomized controlled trial designs make such studies less generalizable. Control groups often realize some benefit; by itself randomization does not preclude this. The issue of chance is answered by statistical analysis, not study design.

Answer 187

B. Attributable risk is the incidence in exposed (risk of stroke with a family history) minus incidence in unexposed (risk of stroke with no family history). In this case, 60/1000 - 100/10,000 = 600/10,000-100/10,000 = 500/10,000 = 5%

Answer 188

D. Both A and C increase the costs for the screening test and the subsequent diagnostic test with no improvement in cases detected or lives saved. The impact of B, holding sensitivity and specificity for mammography would increase the number of false positives which would increase costs through more biopsies for false positives, again with no health benefits. If the cost of late stage breast cancer increases, then averting late stage breast cancers (and the associated treatment costs) would be associated with a lower cost per outcome (here, cost per life year gained).

Answer 189

B. Parity is an ordinal variable describing groups with an inherent order. Regular categorical also known as dichotomous would be yes/no or male/female groups. Continuous would be number measurements and discrete would be integer counts.

Answer 190

C. Alcohol intake of grams per day is a continuous numeric variable. Alcohol intake could be regular categorical if it were recorded as do you drink alcohol — yes or no. Alcohol intake could be ordinal if it were recorded in ordered groups of increasing alcohol intake. Discrete variables represent integer counts.

Answer 191

A. Multivitamin use is a regular categorical variable. It is displayed as a number, but the number represents those answering yes to the question do you take a multivitamin — yes or no. Ordinal variables represents groups of inherent order. Continuous variables represent number measurements and discrete variables represent integer counts.

Answer 192

C. BMI is a continuous variable that is number measurement (e.g. 25.2, 25.4, 26.0, etc.) If the BMI were recorded as BMI groups according to the parameters for underweight, normal weight, overweight, and obese; it would be an ordinal variable. Regular categorical variables are dichotomous. Discrete variables are integer counts.

Answer 193

C. BMI is a continuous variable that is number measurement (e.g. 25.2, 25.4, 26.0, etc.) If the BMI were recorded as BMI groups according to the parameters for underweight, normal weight, overweight, and obese; it would be an ordinal variable. Regular categorical variables are dichotomous. Discrete variables are integer counts.

Answer 194

B. Alcohol intake would have right skewed distribution. The median of 1.8 is much closer to the 25th percentile of 0 than to the 75th percentile of 7.6. This indicates a concentration of values at the lower end with a tail extending at the higher end, consistent with a right skew.

Answer 195

B. A median of 1.8 with an IQR of 0-7.6 represents a right skewed distribution. As the mean is more heavily influenced by outliers than the median, it will be farther into the tail. In the case of a right skew, the mean will be higher so greater than the median. For a right skewed distribution, mode < median < mean.

Answer 196

B. The exposure categories are categorical variables and age is a continuous variable. Because the sample size is great enough to fulfill the central limit theorem and there are >2 exposure groups, ANOVA is necessary to compare the means among the groups. T-test would be appropriate if there were only 2 groups for the categorical variable. Wilcoxon rank sum is the non-parametric counterpart of the t-test and Kruskal Wallis is the non-parametric counterpart of the ANOVA.

Answer 197

D. Both MI at age <60 (yes/no) and exposure groups are categorical variables. The statistical test for comparing proportions of categorical variables is the chi square test. Linear regression is the statistical test for comparing a continuous exposure with a continuous outcome. McNemar’s chi square test is used for comparing paired proportions of categorical variables. The sign test uses percentages of value 1 > value 2 as the input for a chi square test to determine a significant difference in a paired analysis. The percentage is compared to the null expected value of 50%.

Answer 198

C. Dependent variable is another term for outcome and independent variable is another term for predictor or exposure. Here we are trying to determine whether maternal age and BMI (predictors or independent variables) influence infant birth weight (outcome or dependent variable).

Answer 199

D. The statistical test for comparing a continuous exposure variable with a continuous outcome variable is linear regression. The t-test is the parametric statistical test for comparing a categorical exposure variable with a continuous outcome variable. McNemar’s chi square is the paired counterpart to the chi square test for comparing a categorical exposure variable with a categorical outcome variable. Kruskal Wallis is the non-parametric counterpart to the ANOVA for comparing >2 groups.

Answer 200

D. The 95% CI = x̄ ± Z0.975 * (σ/√n). For a sample of 100, Z0.975 ≈ 2. So, the formula is 95% CI = 30 ± (10/√100) = 30 ± 2 = 28.0, 32.0.

Answer 201

C. The population of students within a single school is first stratified into grade level and then randomly sampled, which represents stratified random sampling. Simple random sampling would be selecting a random sample from the entire school population. This could result in missing a grade level and having one grade level over-represented. Cluster sampling would have occurred if a random sample of different elementary schools were collected for comparison. Systematic sampling is alternatively allocating individuals to one group or another.

Answer 202

D. For a normal distribution, Z = (X - μ) / σ. In this example, Z = (3846 - 2405) / 225 = 441 / 225 = 1.96. A Z score of 1.96 corresponds with the 97.5 percentile with 97.5% of values being below 3846 grams and 2.5% of values being above 3846 grams.

Answer 203

A. Rejection of a null hypothesis that is true is a type I error. Failure to reject a null hypothesis that is false is a type II error.

Answer 204

A. With a very large sample size of n=2000, the t-test will approximate the Z-test. A two-sided p-value of 0.05 is associated with a critical value of 2. Since the Z-score of 3.5 is much larger than the critical value of 2, we can reject the null hypothesis and claim a statistically significant difference between pre- and post-test scores.

Answer 205

B. For differences in means, the null value is 0. Since the 95% CI includes the null value, we do not have evidence to reject the null hypothesis that there is no difference between exercising and non-exercising mothers.

Answer 206

B. For differences in means, the null value is 0. Since the 95% CI includes the null value, we do not have evidence to reject the null hypothesis that there is no difference between exercising and non-exercising mothers.

Answer 207

A. ANCOVA is an adjusted mean controlling for the possible influence of another variable. It is derived from a linear regression model used to compare continuous exposure (age) and outcome (length of hospital stay) variables.

Answer 208

B. for every 10% increase in alcohol taxes, the rate of death from cirrhosis is reduced by 7%

Answer 209

B. for every 10% increase in alcohol taxes, the rate of death from cirrhosis is reduced by 7%

Answer 210

A. Employer-sponsored insurance is the most common. 54.5% employer-based coverage 18.8% Medicaid 18.7% Medicare 9.9% direct-purchase coverage 2.4% TRICARE 1.0% VA and CHAMPA [https://www.census.gov/library/publications/2023/demo/p60-281.html]

Answer 211

A. Employer-sponsored insurance is the most common. 54.5% employer-based coverage 18.8% Medicaid 18.7% Medicare 9.9% direct-purchase coverage 2.4% TRICARE 1.0% VA and CHAMPA [https://www.census.gov/library/publications/2023/demo/p60-281.html]

Answer 212

D. Participation measures fall under the foundation of Health-Related Quality of Life and Well-Being and reflect individuals’ assessments of the impact of their health on their social participation within their current environment. A practitioner’s assessment of ADLs would fall under the foundation of General Health Status.

Answer 213

B. MCOs are systems of administrative controls aimed at managing the cost of healthcare, access to healthcare, and quality of healthcare in defined populations

Answer 214

B. According to Donabedian’s categories of measuring quality, process measures are what is actually done in giving or receiving care and outcome measures are the effect of an intervention on health status, clinical findings, or perceptions of care.

Answer 215

C. Indirect costs include days lost from work and reduced productivity. Direct medical costs encompass drugs, labs, hospitalizations, etc. Direct non-medical costs encompass transportation, lodging for family during a hospitalization, etc. Intangible costs encompass pain, psychological harm, etc.

Answer 216

D. The ICER = (CTx1 - CTx2) / (ETx1 - ETx2). Tx1 in this case is the new drug and Tx2 is the gold standard. Average cost per cure for Drug A = $500/0.95 = $526. Average cost per cure for Drug B = $750/0.97 = $773. Thus, the ICER = ($773 - $526) / (0.97 - 0.95) = $12,500. So, Drug B will cost $12,500 per additional cure.

Answer 217

B. Annex 6, item 7 of the IHR (2005) states that "International certificates of vaccination are individual certificates and shall in no circumstance be used collectively. Separate certificates shall be issued for children." International Certificates are required to be signed and stamped with the uniform stamp by the medical provider or other person authorized by the national health administration. Members of the armed forces may use similar vaccination records if they contain the same information.

Answer 218

C. The DOT Act of 1966, which created the DOT, also created the NTSB. At that time, the Safety Board was placed under the DOT for certain administrative and housekeeping functions. Congress directed that the Safety Board was to function "independently of the department of transportation and report annually to the Congress." The Independent Safety Board Act of 1974 made the Board an independent agency by the Federal Government. This act expanded the Board's responsibilities for safety in the surface transportation modes of highway, rail, pipeline, and marine. The civil aviation responsibilities under the new act remained unchanged. The mission of the Safety Board is to determine the cause of transportation accidents and to make recommendations to prevent such accidents from recurring. The NTSB determines the causes of all US civil aircraft accidents through investigations, public hearings, and staff analysis of accident information.

Answer 219

A. Vestibular abnormalities, postural hypotension, and mobilization of calcium (bone demineralization) are all recognized sequelae of space flight. Although transient changes in pulmonary function are initially seen (thought to be related to fluid shifts in the microgravity environment), these revert to normal within a few days of space flight (FVC and FEV1 return to baseline). The ISS and Soyuz atmospheres are nominally the same as ground level and significant pulmonary function shifts were not seen with earlier space exploration in lower pressure, 100% O2 environments. {Davis (2022), p. 517}

Answer 220

A. Using accidents per 100,000 flying hours does not equally assess risk between types of aircraft in that higher risk phases of flight are takeoff and landing. Exposure to these phases of flight per 100,000 flying hours is much greater in fighter aircraft and small general aviation with short flight times per flight. Ground and taxi time are included in the definition of flight mishap. Rate measurement specifically overcomes the difference in total number of hours flown. Distance flown is not part of the rate calculation. Slower flight does not increase risk unless the aircraft is exposed to more takeoffs and landings.

Answer 221

D. Heel walking tests the L5 nerve root. Saddle anesthesia indicates a central disc herniation with possible cauda equina syndrome with pressure on multiple lumbar and sacral nerve roots inside the spinal canal. Quadriceps weakness would indicate a higher lesion at L3/4 disc or the L4 root. Diminished ankle jerk implies an S1 root lesion at the L5/S1 disc level.

Answer 222

D. Many allergens (e.g. nickel, epoxies) are in widespread use outside of the workplace and may cause persistent symptoms. Acute contact dermatitis is a Type IV (delayed-type hypersensitivity/cell-mediated) reaction. Contact urticaria would be a Type I reaction. Because of the systemic nature, lesions may extend beyond sites of contact. Sensitization may be idiosyncratic and only affect a few exposed workers.

Answer 223

B. The combination of sunlight exposure and volatile polycyclic aromatic hydrocarbons (PAHs) coming from asphalt shingles increases risk for squamous cell carcinoma. Lead has no known role in skin cancer. Radiographic exposures for doctors are likely much too small for carcinogenesis. Photographic printers have risk of depigmentation/vitiligo, but not cancer.

Answer 224

B. RADS is persistent airways reactivity to non-specific stimuli after an inhalation injury or event. Inhalation fevers are acute, limited (<24 hrs) reactions to organic dusts, metals, or polymer fumes. Occupational asthma is reserved for asthma symptoms caused by allergic sensitization in the workplace as distinct from the single irritant exposure in this question. Hypersensitivity pneumonitis has a more prolonged symptomatology to allergens primarily large molecular weight biological allergens.

Answer 225

1. Parkinsonism — C. Manganese 2. Encephalopathy — C. Manganese 3. Trigeminal neuralgia — A. Trichloroethylene 4. Ataxia — D. Methylmercury

Answer 226

D. High-pitched sibilant consonant sounds (st, sh, ch) are often confused in speech early in NIHL. Generally pure-tone thresholds mus be about 30-40 dB in the speech frequencies (500-3000 Hz) for NIHL to be recognized by a worker. 25% of workers exposed at the OSHA PEL will develop NIHL across a working lifetime. The NIOSH REL and EU regulations specify 85 dB as protective of most workers (~8% will develop NIHL at these levels). NIHL is irreversible. Screening audiometry helps to detect subclinical cases that can then be reassigned or take other measures to limit noise.

Answer 227

C. Cadmium is associated with osteomalacia. Lead is traditionally noted for causing a motor neuropathy (foot/wrist drop) although sensory symptoms are evident to a lesser extent. Arsine (AsH3) causes massive intravascular hemolysis while arsenic causes hyperpigmentation. Chromium may cause lung cancer but not interstitial lung disease. Metals like beryllium, cobalt, and nickel carbonyl may cause interstitial lung disease.

Answer 228

C. Cadmium is associated with osteomalacia. Lead is traditionally noted for causing a motor neuropathy (foot/wrist drop) although sensory symptoms are evident to a lesser extent. Arsine (AsH3) causes massive intravascular hemolysis while arsenic causes hyperpigmentation. Chromium may cause lung cancer but not interstitial lung disease. Metals like beryllium, cobalt, and nickel carbonyl may cause interstitial lung disease.

Answer 229

D. The relative risk due to diarrheal disease, even in infants only partially breastfed, is more than 4x higher than infants who are exclusively breastfed in developing nations. Relative risk of pneumonia is also more than doubled. Both these adverse consequences may be largely attributed to the loss by formula feeding of passive transfer of protective antibodies from the mother’s breast milk.

Answer 230

C. The newer HepB-CpG vaccine, approved in 2018) has a higher overall seroconversion rate and is given in a two dose series over only one month. While the single booster of the orignal HBV vaccine and a re-check of the titer in one month might work, it still occasionally fails and the three dose series must be completed anyway.

Answer 231

A. C. Difficile spores are resistant to alcohol-based hand sanitizers. Regular hand-washing is more effective for eliminating spores, along with the other measures listed to reduce the potential for nosocomial infections in other patients.

Answer 232

C. RPR titres are used to manage and follow treatment of syphilis. Successful prior treatment will result in a least a four-fold drop in titre. If RPR titer before treatment was 1:32 and is now 1:4, this would indicate successfully treated primary syphilis and no further treatment would be required. Doxycycline would be contraindicated during pregnancy even if treatment were appropriate.

Answer 233

C. A review of Zika testing utilizing multiple methods and sources done by the Florida Department of Health Bureau of Public Health Laboratories was published in MMWR on over 900 possible Zika virus cases or which 91 were later confirmed. No results from serum RT-PCR were positive >5 days after symptom onset while results from urine RT-PCR were positive after 5 days. RT-PCR of both serum and urine was felt to deliver the most rapid and specific diagnosis during the first 7 days of symptomatic illness. After the first week, only urine RT-PCR is recommended for the second week. If RT-PCR is negative, IgM-Elisa may be performed. However, this test has cross-reactivity with other flaviviruses such as dengue, yellow fever, and West Nile virus that are commonly found in areas with Zika. If IgM-ELISA is positive, if must be confirmed by a plaque reduction neutralization test (PRNT) to identify Zika.

Answer 234

A. Lassa virus, an Old World arenavirus, is the etiological agent of Lassa fever, a severe human disease that is reported in more than 100,000 patients annually is the endemic regions of West Africa with mortality rates for hospitalized patients varying between 5-10%. Nosocomial transmission has been recorded and is associated with higher case fatality rates. Anthrax is acquired by inhaling aerosolized spores or by ingestion or skin contact. It is not directly transmitted to person-to-person. Botulinum toxin used as a biological weapon would be disseminated via aerosol or contaminated food or water and is not transmitted person-to-person. Tularemia has been transmitted by hunting and skinning infected rabbits and other animals or through fleas or ticks. It is not transmitted person-to-person.

Answer 235

C. Percent of deaths in a given population is proportional mortality. Incidence is required in order to calculate attributable risk or relative risk, but is not provided in this question.

Answer 236

D. Incidence is the proportion of new cases in the population at risk. The incidence of prostate cancer in this example 5 new cases per year per 1,000 men at risk. So, in a population at risk (disease-free men) of 10,000, after 1 year 10,000 * (5/1,000) = 50 men would develop new prostate cancer. In the second year, the population at risk would be 10,000 - 50 = 9,550. So, in the 2nd year, 9,550 * (5/1,000) = 49.75 or 50 men would develop new prostate cancer. Prevalence is the proportion of existing cases in the total population. After 2 years 50 + 50 = 100 men developed prostate cancer. So the 2 year prevalence of prostate cancer is 100/10,000 = 10/1,000.

Answer 237

A. The risk of any 1 US male dying from prostate cancer is 1 in 40 or 1/40=0.025 or 2.5% as provided in the question. Case fatality rate cannot be determined from the data provided as it is equal to the number dying from disease / number with disease. The number of people prostate cancer is not given. Lung cancer is the leading cause of cancer deaths overall and the leading cause of cancer deaths in men. Prostate cancer is the second leading cause of cancer deaths in men. Incidence cannot be determined from the data provided as it is the proportion of new cases / number at risk. The total population at risk for prostate cancer is not given.

Answer 238

B. & C. Specificity is true negatives / (true negatives + false positives) and sensitivity is true positives / (true positives + false negatives). Picking a higher cut-off makes it harder to have a positive test, thus decreasing the number of false positives and the number of true positives. As the number of false positives decreases, the specificity increases. And, as the number of true positives decreases, the sensitivity decreases. Defining a positive cancer screening test as 4.0 or above would mean that 1 in 5 or 1/5=0.20 or 20% of positive tests would actually have cancer as provided in the question. This represents the positive predictive value or how often positive test reflect true positives. Defining a positive cancer screening test as 10.0 or above would mean that 60% of men would actually have cancer. Thus, 40% of men would be false positives.

Answer 239

B. Taking the incidence in the study as the prevalence, the total population with prostate cancer would be 1,653 * 0.022 = 36 and the population without would be 1,653 - 36 = 1,617. The sensitivity reveals that there were 36 * 0.79 = 28 true positives and 36 - 28 = 8 false negatives. The specificity reveals that there were 1,617 * 0.59 = 954 true negatives and 1,617 - 954 = 663 false positives. The positive predictive value is true positives / (true positives + false positives) = 28 / (28 + 663) = 0.04 or 4%.

Answer 240

D. Taking the incidence in the study as the prevalence, the total population with prostate cancer would be 1,653 * 0.022 = 36 and the population without would be 1,653 - 36 = 1,617. The sensitivity reveals that there were 36 * 0.79 = 28 true positives and 36 - 28 = 8 false negatives. The specificity reveals that there were 1,617 * 0.59 = 954 true negatives and 1,617 - 954 = 663 false positives. The negative predictive value is true negatives / (true negatives + false negatives) = 954 / (954 + 8) = 0.99 or 99%.

Answer 241

A., B., C., & D. Considerations for screening implementation include downstream effects of testing such as the consequences of false positives and methods to improve PPV/NPV. Conducting prostate cancer screening with PSA in parallel with another test would mean a screen would be positive if either test were positive. This strategy makes it easier to be positive, thus letting in more false positives and decreasing the PPV. Conducting prostate cancer screening with PSA in series with another test would mean a screen would be positive only if both tests were positive. This strategy makes it harder to be positive, this letting in more true positives and increasing PPV. Implementing the PSA test in high-risk groups would increase the prevalence of the prostate cancer in the screened population and would thus increase PPV.

Answer 242

B. Attributable risk is the risk in exposed individuals that can be attributed to the exposure or the (Iexp) - (Iunexp) = (a/n1) - (c/n2). In this example, AR = (29/1,218) - (23/1,207) = 0.0048.

Answer 243

C. Relative risk is the ratio of the incidence of a condition in the group of individuals with a specific risk to the incidence in the group of individuals without the risk. In this question group considered to have the risk is the 66-70 age group. RR = (Iexp) / (Iunexp) = (a/n1) / (c/n2) = (24/850) / (9/683) = 2.1.

Answer 244

A., B., & C. The null value for RR is 1. If statistically significant, age 66-70 would be associated with a 2.1x increased risk for prostate cancer compared to age 50-60. The null value for AR is 0. If statistically significant, the presence of urinary complaints would be a risk factor for prostate cancer as 0.0048 > 0. For an association to be the result of confounding, the confounding variable must be associated with both the outcome and the exposure. In this case, urinary complaints increase with age and prostate cancer increases with age, making confounding a possibility. The appropriate test of significance is driven by the type of variables assessed. If the outcome is continuous (e.g. weight) and the variable is categorical (e.g. M/F), summarize with means and standard deviation and analyze with a t-test. If the both the outcome and variable are categorical as in this example with prostate cancer (Y/N) and urinary complaints (Y/N), summarize with rates and proportions and analyze with chi-squared.

Answer 245

A., B., & C. The study from 1985 is an example of a case-series. This is a type of descriptive study that describes only an exposed group without a control group. Descriptive studies can only establish non-causal associations. Referral bias arises from patients referred to a university hospital being different in characteristics that may influence the prevalence of the disease in that setting. A case-control study starts with an outcome and works backward to an exposure. Since prostate cancer is estimated to be relatively rate at 0.5% of the population, a case-control study is the best observational study to assess the exposure of vasectomy.

Answer 246

A., B., C., & D. This is a case-control study that started with the outcome of prostate cancer and looked back for the exposure to vasectomy. This study runs the risk of selection bias if men admitted to the orthopedic ward were more likely to have had a vasectomy than the general population. This would bias the results of the study and underestimating the association between vasectomies and prostate cancer. This study runs the risk of detection bias if urologists, who perform most vasectomies in the US, were more aggressive at looking for prostate cancer than other healthcare providers. In this case, men who get vasectomies may be more likely to have a cancer detected than men who don’t have a clinical relationship with a urologist. This would tend to lead to an overestimation of the association between vasectomies and prostate cancer. Vasectomy status could be a confounder in this study. Hypothesizing that men who get vasectomies tend to have less frequent sexual intercourse, which may be associated with prostate cancer, compared to men that don’t have vasectomies could account for the apparent association between vasectomies and prostate cancer.

Answer 247

A. & C. This proposed study represents a prospective cohort study. It is a cohort design compares men with or without the exposure to the urology clinic for the outcome of prostate cancer. Since it looks from the time of the exposure forward to the outcome, it is prospective in design. A cohort study is more robust than a case-control study. It has the same structure as an RCT except that in an RCT subjects are randomly assigned to the exposure.

Answer 248

A. & C. Cohort studies compare individuals with or without an exposure for an outcome either prospectively or retrospectively. A major concern for these studies is loss to follow-up. Confounding is a potential problem in any study. In terms of practicality, cohort studies are slower and more expensive than case-control studies. A simple way to think about observational study design is to start with whatever is rarest. If the exposure is rare, use a cohort study. If the outcome is rare use a case-control study. Another way is by end point. If you want to see multiple outcomes, use a cohort study. If you want to see multiple exposures, use a case-control study.

Answer 249

A. & C. Cohort studies compare individuals with or without an exposure for an outcome either prospectively or retrospectively. A major concern for these studies is loss to follow-up. Confounding is a potential problem in any study. In terms of practicality, cohort studies are slower and more expensive than case-control studies. A simple way to think about observational study design is to start with whatever is rarest. If the exposure is rare, use a cohort study. If the outcome is rare use a case-control study. Another way is by end point. If you want to see multiple outcomes, use a cohort study. If you want to see multiple exposures, use a case-control study.

Answer 250

A., B., C., & D. Causes are factors that are both sufficient and necessary for an outcome and usually are only used for infectious disease. Causal associations are factors that are sufficient but not necessary for an outcome. An association should be strong (strength of association is seen in D. with statistical significance) and should particularly be strongest when expected (i.e. a biological gradient as in C.). Further, associations should be consistent (meta-analysis of 3 studies shows a consistent RR in B.) and plausible (biological plausibility in A.)

Answer 251

B. & D. Primary prevention is the prevention of disease development. Since there are no known modifiable risk factors for prostate cancer, there is no method for primary prevention. One method to improve PPV in the screening for a rare disease is to screen for the disease in a high-risk population. Since the non-modifiable risk factors of age and race are associated with prostate cancer. These could be utilized to screen a population in which prostate cancer is more prevalent, thereby increasing the PPV. Removal of the prostate gland could be primary, secondary, or tertiary prevention depending on whether cancer had developed in the prostate. In order to propose prostate gland removal as a strategy, a cost-benefit analysis would need to be performed. Considering how the treatment is linked to reduced morbidity/mortality, the association between intermediate outcomes of treatment and reduced morbidity/mortality, and the adverse effects of treatment; prostate gland removal is not likely to be a net benefit. Sexual activity, like vasectomy, is a modifiable risk factor and is concluded to not be significant for prostate cancer.

Answer 252

A., B., C., & D. All of the above are factors that should be considered in selecting a screening test are: (1) how screening method is linked to reduced morbidity/mortality — answer choice B. (2) persons at risk — answer choice A. Prevalence drives almost everything. If the prevalence is higher in the study population the strategy would have a higher PPV than it would in the general population. (3) screening method (4) treatment method that results from early detection (5) how treatment method is linked to reduced morbidity/mortality — answer choice C. (6) association between intermediate outcomes of treatment and reduced morbidity/mortality (7) adverse effects of screening — answer choice D. (8) adverse effects of treatment

Answer 253

A. & C. An RCT compares individuals with and without an exposure for an outcome. This is the same as a cohort study except that, in an RCT, the investigator randomly assigns individuals to have or not have the exposure. Study design is a trade-off between multiple factors. While making groups comparable is a method for reducing confounding, it also makes the findings less generalizable to the general population. Loss to follow-up is a problem for any prospective study and studies should always analyze data with an intention to treat, such participants who dropped out or crossed over to another group are analyzed as if they had remained. While an RCT by definition randomly distributes confounders between groups and is a method for reducing confounding, potential confounders should always be considered in the final analysis.

Answer 254

A., B., & C. Bias in RCTs can be reduced through double blinding. Blinding of investigators and participants can limit observation bias. Cross-overs in an RCT always drive toward the null, underestimating the benefit of the intervention. A screening strategy is ideally for secondary prevention, detecting an asymptomatic disease at an early stage. Screening should also seek to reduce mortality as well as morbidity. Looking only at deaths could result in lead time bias if the disease is detected earlier, but there is no reduction in mortality.

Answer 255

B. & D. An epidemic curve would be helpful in this situation, for instance determining whether endocarditis cases are elevated at both study sites or only one. In order to determine if an epidemic exists, the current case level must be compared to the expected endemic level. Without knowing the endemic level in this question, the number to determine an epidemic cannot be determined. Endocarditis, though not a primary endpoint, could represent an adverse effect from the intervention and should be reported.

Answer 256

B. Attack rate is number with disease divided by the total population. In this case attack rate = 11 cases of endocarditis / 122 ultrasound subjects = 9.0%.

Answer 257

D. Relative risk is the incidence in exposed divided by the incidence in unexposed. In this case, RR = (7/44) / (18/201) = 1.8.

Answer 258

B. & D. An epidemic source exposure can be determined by calculating the attack rate for each exposure and determining the relative risks. Site 1 attack rate = 3/130 = 0.023 Site 2 attack rate = 22/115 = 0.191 RR = 0.191/0.023 = 8.3 U/S attack rate = 11/122 = 0.090 No U/S attack rate = 14/23 = 0.114 RR = 0.114/0.090 = 1.3 Biopsy attack rate = 20/91 = 0.220 No biopsy attack rate = 5/154 = 0.032 RR = 0.220/0.032 = 6.8 TURP attack rate = 7/44 = 0.159 No TURP attack rate = 18/201 = 0.090 RR = 0.159/0.090 = 1.8 While the results do show that hospital site was an important predictor, they indicate that the epidemic may be related to something at site 2. Additionally, the epidemic may be related to having a biopsy more so than TURP.

Answer 259

A. Virulence has to do with an agent’s ability to produce severe disease (e.g. LD50 is dose of agent necessary to kill 50% of hosts). Infectivity is an agent’s ability to multiply in a host, establishing an infection (e.g. ID50 is dose of agent necessary to infect 50% of hosts). Infectiousness is an agent’s ability to be transmitted to from one host to another host. Immunogenicity is an agent’s ability to elicit a host immune response.

Answer 260

B. & C. The incubation time is the period between exposure to an agent and onset of symptoms. In this case, it is 48 hours. This represents a point source epidemic with the improperly sterilized biopsy needles being the common source. Secondary attack rate and propagated epidemics are associated with ongoing person-to-person spread.

Answer 261

A., B., C., & D. The study in question is a case-control study, which follows the following steps — case definition, case selection, control selection, and analysis. Any step along the way represents a potential source of bias. Ways to reduce selection bias in the study are a strict and uniformly-applied case definition and generalizable selection of subjects. Observer bias in the analysis step can be reduced through blinding of investigators. The analysis should also account for all exposures and potential confounders.

Answer 262

C. This is a randomized controlled trial.

Answer 263

D. This is a case-control study.

Answer 264

B. This is a retrospective cohort study.

Answer 265

E. This is a cross-sectional study.

Answer 266

D. This is a case-control study and more specifically a nested case-control as it is nested within a cohort study.

Answer 267

A., B., C., & D. More sensitive tests make it easier to have a positive test, thus increasing the number of false positives and the cost to sort out the positive tests. As prevalence increases, positive predictive value increases and the cost per case detected decreases. A low specificity would decrease the number of true negatives, increasing the number of false positives. Thus, the strategy would be influenced by the increased cost of sorting out the positive tests. An effective screening program identifies asymptomatic disease before late stage treatments are necessary. Thus, reducing the need for expensive late stage treatments, increases the cost-effectiveness of a screening program.

Answer 268

C. TSCA only regulates chemicals, e.g. ammonia. Nuclear material is covered under the Atomic Energy Act. Though pesticides are chemicals they are regulated by their own act, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).

Answer 269

D. The EPA is responsible for collecting data to characterize potential health risks of pesticide exposure. They use these data to establish pesticide residue levels in food. Enforcement of the pesticide residue levels in food falls to the FDA however. Establishment of workplace exposure standards is the job of OSHA. Ensuring no toxic effects occur is not possible.

Answer 270

B. Individual health risk appraisals intend to determine both healthy and unhealthy behavioral practices.

Answer 271

A. A follow-up study of the original Health Belief Model publication showed that perceived susceptibility to contracting a disease is the strongest contributor to understanding of preventive services. Janz NK, Becker MH. The health belief model: A decade later. Health Education Quarterly 1984;11(1):1-47.

Answer 272

C. The Theory of Planned Behavior is an extension of the Theory of Reasoned Action to include perceived behavioral control. The Health Belief Model has six constructs that include perceived susceptibility, perceived severity of disease, perceived benefits of change, perceived barriers to change, cues to action, and self-efficacy. Reciprocal determinism and observational learning are key constructs in social learning theory. The PRECEDE/PROCEED model is a road map for using behavior theories and is not itself a behavior theory.

Answer 273

B. Rothman’s typology entwines locality development with social planning and social action.