Board Review Flashcards
A reduced oxygen pressure differential across the alveolar-capillary barrier is associated with:
a. Hypoxic hypoxia.
b. Hypemic (anemic) hypoxia.
c. Stagnant hypoxia.
d. Histotoxic hypoxia.
a. Hypoxic hypoxia is caused by a reduction in the partial pressure of alveolar oxygen as with altitude exposure. A reduction in alveolar pressure will cause a decrease in the oxygen pressure differential across the alveolar-capillary barrier. This, in turn, results in an inadequate saturation of arterial blood and a subsequent decrease in the amount of oxygen carried to the tissues. The only type of hypoxia in which there is a reduction in pressure across the alveolar-capillary barrier is hypoxic hypoxia. Hypemic hypoxia results from insufficient blood oxygen-carrying capacity (e.g. anemia, CO poisoning). Stagnant hypoxia results from hypoperfusion (e.g. increased G, cardiac failure). Histotoxic hypoxia results from su cellular failure of oxygen utilization (e.g. cyanide poisoning).
{Davis (2022), p. 308}
Man can generally tolerate an appreciable decrease in the ambient barometric pressure because of the:
a. Increased blood flow to the brain with hyperventilation.
b. Constant percentage of oxygen in the ambient air.
c. Shape and shifting of the oxygen dissociation curve for hemoglobin.
d. Shift toward a state of respiratory alkalosis.
c. The explanation of the role of the oxygen dissociation curve in tolerance of decreased barometric pressure involves two facets. First, the shape of the curve, flattening near its top where hemoglobin is highly oxygenated, means that hemoglobin remains significantly saturated until the partial pressure of oxygen drops quite low. Secondly, as the partial pressure of oxygen drops, hyperventilation is initiated resulting in a respiratory alkalosis. As the blood pH rises, the dissociation curve shifts to the left allowing for a greater
percentage of oxygen saturation of hemoglobin at a given oxygen partial pressure, i.e., the affinity of hemoglobin for oxygen increases.
{Davis (2022), p. 61}
Which of the following is true regarding the 47 mmHg of water vapor pressure exerted with those gases involved in pulmonary physiology?
a. It is not affected by temperature.
b. It is not affected by altitude.
c. This pressure is reduced by one-half at 18,000 ft.
d. It must be disregarded when calculating the partial pressures of inspired gases.
b. Water vapor pressure is temperature dependent only, and at a body temperature of 37 degrees C exerts 47 mmHg of pressure. The partial pressure of oxygen (PIO2) entering the alveolar space is estimated by subtracting saturated water vapor pressure at body temperature (PH2O) from ambient barometric pressure (PB) and then multiplying by the fractional inspired oxygen concentration (FIO2), 21% when breathing air. Both water vapor and carbon dioxide will account for increasing proportions of the total alveolar gas pressure with steady altitude exposure. {Davis (2022), p. 311} Air pressure is 50% of sea level (760 mmHg) at 18,000 ft (380 mmHg), which would not have any impact on water vapor pressure. {Davis (2022), p. 302-303}
A pilot, who has just departed base and is performing a steep climbing left turn, turns his head to the console on his right to change the radio frequency to departure control. He may experience:
a. Oculogravic illusion.
b. Coriolis illusion.
c. Autokinesis.
d. Flicker vertigo.
b. The pilot moved his head in a plane that cut across the plane of rotation of an already rotating system which could result in coriolis illusion. The coriolis is illusion results from unusual stimulation of the semicircular-duct system. Rotation in the yaw plane long enough for endolymph to stabilize in the horizontal semicircular duct, followed by moving the head across the plane of rotation would result in perception of rotation in the new plane of the semicircular duct without rotation actually occurring in that plane. {Davis (2022), p. 409}
The oculogravic illusion is the visually apparent movement of an object that is actually in a fixed position relative to the subject during a change in direction of the net gravitoinertial force. {Davis (2022), p. 413}
Autokinesis is the perception that a light viewed against a dark background is moving when it is in fact stationary. This may occur after 6-12 seconds of visual fixation on the light and can result in appearance of movement of 20 degrees or less in one or more directions. {Davis (2022), p. 402}
Flicker vertigo may be induced by light flickering through a spinning rotor on a helicopter or idling propellers on an airplane. {Davis (2022), p. 426}
If an aircraft crashes during a controlled flight into the ground and there is no evidence that the pilot was aware of the impending collision or made no control response to prevent the aircraft from flying into the ground, the pilot most likely experienced:
a. Type I spatial disorientation
b. Type II spatial disorientation
c. Type III spatial disorientation
d. Spatial disorientation without loss of situational awareness
a. Controlled flight into terrain always suggests the possibility of spatial disorientation. Since the pilot appears to have been unaware of his or her spatial disorientation episode, Type I spatial disorientation is the appropriate category in this instance. Type I SD is unrecognized, type II SD is recognized, and type III SD is incapacitating. {Davis (2022), p. 416}
The vertical heart-to-eye distance in a typical seated fighter pilot is 29 cm. He will begin to lose peripheral vision if his eye-level systolic blood pressure drops below about 50 mm Hg, and total visual loss (blackout) will occur if eye-level systolic blood pressure drops below 20 mm Hg. If this pilot has a heart-level systolic pressure of 120 mm Hg and is afforded no G protection from an anti-G suit or by performing the anti-G straining maneuver, at what +Gz level would you predict him to black out? One mm Hg is equivalent to 1.29 cm of blood.
a. 0.9 G
b. 3.6 G
c. 4.4 G
d. 5.3 G
c. Pressure drop (mm Hg) = (hydrostatic column (cm) x G) / (1.29 cm blood/mm Hg)
120 - 20 = 29 x G / 1.29
G = 100 x (1.29/29)
G = 4.4
Galactic cosmic radiation:
a. Consists of mostly electrons and high energy nuclei of heavier atoms.
b. Is of little consequence within spacecraft, but may be harmful during extravehicular activities.
c. Consists of about 90% protons, and 9% helium nuclei (alpha particles).
d. At sea level has only 40% of the ionizing power it has at 70,000 feet.
c. High-energy particles consisting of protons (90%), alpha particles (9%), and nuclei of heavier atoms (1%) originating from either the sun or other stars, pose probably the single greatest threat to long-duration interplanetary space travelers. {Davis (2022), pp. 478-479; Barratt (2019), p. 49}
You are trekking with a group that has just reached a base camp at 14,500 feet. One of your fellow trekkers begins complaining of shortness of breath and cough. You listen to his chest and discover diffuse wheezing in the right upper lobe as well as a respiratory rate of 30. Your diagnosis is:
a. Acute mountain sickness (AMS).
b. High altitude pulmonary edema (HAPE).
c. High altitude cerebral edema (HACE).
d. Pneumonia.
b. In the setting of a recent gain in altitude, a patient with at least two of the following signs and symptoms meets the criteria for HAPE: shortness of breath at rest, cough, weakness or decreased exercise performance, chest tightness or congestion, rales, wheezing in at least one lung field, central cyanosis, rapid breathing, and rapid heart rate. {Davis (2022), pp. 306-307}
Retreating blade stall experienced by a helicopter in flight is caused by:
a. Insufficient airframe forward airspeed.
b. Excessive airframe forward airspeed.
c. Aggressive yawing maneuvers.
d. Rearward flight.
b. The retreating blades of a helicopter in flight experience a relative wind that consists of blade rotation velocity minus the forward airframe airspeed. Excessive airframe forward airspeed thus lowers the amount of relative wind available for the retreating blades and, in extreme cases, can cause these blades to stall. Avoid retreating blade stall by not exceeding Vne. {FAA Helicopter Flying Handbook (2019), p. 2-20}
While backpacking with a group of adults in mid-afternoon one hot July day, one of the members of the group becomes quite lethargic, confused, and subsequently faints. He rouses quickly but has an ashen-grey appearance. Examination of the individual reveals the following: cold and clammy skin; pupils somewhat dilated; pulse slightly elevated; otherwise temperature appears normal without any other abnormal signs. He has no history of medical problems and we are considering his problem to be related to heat stress. In regard to heat overexposure, select the most likely diagnosis and best initial therapy.
a. Heat cramps–loosen clothing and remove the patient to cool area.
b. Heat exhaustion-loosen clothing and remove the patient to cool area.
c. Heat stroke-heroic emergency measures including ice immersion immediately.
d. Heat stroke-remove from heat and immediately give 0.5 cc epinephrine 1:10,000 and begin ice water immersion.
c. The key points in the exam are cold and clammy skin and normal appearing body temperature. The short time of unconsciousness is also important. The therapy for heat exhaustion is rest and removal from heat exposure. {Davis (2022), p. 501}
Which part of the eye is the most vulnerable to microwave radiation?
a. Cornea
b. Iris
c. Lens
d. Retina
c. The energy of microwaves is too low to produce photochemical reactions in humans, but this type of
radiation is absorbed by tissues with a resulting rise in temperature. It follows, then, that the organs in the body most susceptible to microwaves are those organs with the least ability to dissipate heat, and this ability is directly related to the magnitude of blood flow to the organ. The lens does not have a direct blood supply and thus cannot dissipate heat easily which makes it susceptible to microwave-induced heating. {Barratt (2019), p. 68}
The goal of cockpit automation (auto-pilots, navigation systems, adaptive control devices, etc.) is to improve mission capability and increase safety. Experience with highly automated cockpits shows that:
a. The workload of the pilot may increase.
b. The percentage of accidents attributed to “pilot error” has decreased significantly.
c. Use of automated systems reduces and simplifies the pilot’s tasks.
d. With computer-based systems working behind the scenes, cockpit complexity has decreased.
a. The early 1980’s saw the introduction of “glass cockpits” in transport aircraft. These automated cockpits, drawing on microcomputer technology, were designed to improve the presentation of flight data and to aid directly in navigation and flight control. Pilots soon found, however, that one set of problems had been replaced by another. Inputting data, monitoring the automated systems, ascertaining the “mode” of the autopilot system at any given time - all required more pilot attention than anticipated. Indeed, some aircraft crashed because flight crews misinterpreted autopilot information.
What is the minimum age requirement for applying for an aviation medical certificate?
a. 21 years old
b. 18 years old
c. There is NO age requirement
d. 16 years old
C. There is no age restriction or aviation experience requirement for medical certification. Any applicant who qualifies medically may be issued a Medical Certificate regardless of age.
The AME may issue any class of medical certificate without regard to age to any applicant who meets the appropriate medical standards.
There is a maximum age requirement for certain air carrier pilots. This is an operational requirement, not a medical certification requirement.
{AME Guide, General Information, para. 9}
The FAA designees regarding medical certification matters and the link between an applicant /airmen and the FAA is the :
a. FAA Regional Administrator
b. Aviation Medical Examiner
c. Regional Flight Surgeon
d. Federation Air Surgeon
B. Aviation Medical Examiner
An applicant’s medical history indicates a fully explained and documented vaso-vagal episode due to prolonged standing position. The examiner should:
a. DENY medical certification because of LOC
b. DEFER issuance of medical certificate and forward all medical records to FAA
c. Explain the event in Block 60, issue the aviation medical certificate and forward all medical records to the FAA
d. Require a complete neurologic consultation, DEFER and forward all documents to FAA for disposition
C. Explain the event in Block 60, issue the aviation medical certificate and forward all medical records to the FAA. One or two episodes of dizziness or even fainting may not be disqualifying. For example, dizziness upon suddenly arising when ill is not a true dysfunction. Likewise, the orthostatic faint associated with moderate anemia is no threat to aviation safety as long as the individual is temporarily disqualified until the anemia is corrected. If the cause of the disturbance is explained and a loss of consciousness is not likely to recur, then medical certification may be possible.
{AME Guide, Item 46}
When a violation of federal criminal law is committed because of a DQ condition is deliberately NOT reported by applicant or AME, and the condition is observed during an examination or otherwise known to exist by the AME, the:
a. Applicant and examiner can be held responsible
b. Applicant will be held solely responsible
c. Examiner will be held solely responsible
d. FAA will assume the responsibility
A. Applicant and examiner can be held responsible
{cf. AME Guide, General Information, para. 1}
Special Issuance is authorized in accordance with:
a. 14 CRF 67, Section 67.401 and guidelines provided by the Federal Air Surgeon to the Aerospace Medical Certification Division Regional Flight Surgeon
b. Guidelines provided in the primary course, “The School of Aerospace Medicine” WPAFB, Dayton, Ohio
c. The 2012 edition of the Physician’s Desk Reference
d. 14 CFR 61, Certification: Airmen, Flight Instructions, Ground Instructions
A. At the discretion of the Federal Air Surgeon, an Authorization for Special Issuance of a Medical Certificate (Authorization), with a specified validity period, may be granted to an applicant who does not meet the established medical standards under Title 14 of the Code of Federal Regulations (14 CFR) §67.401.
{AME Guide, AASI Coversheet}
Within how many days must an AME transmit an exam in AMCS
a. 3 days
b. 5 days
c. Within 24 hours
d. 14 days
D. All completed applications and medical examinations, unless otherwise directed by the FAA, must be transmitted electronically via AMCS within 14 days after completion to the AMCD.
{AME Guide, General Information, para. 18}
Non-physicians are NOT allowed to perform aviation medical examinations because:
a. Congressional legislation prohibits use of physician extenders in medical practices
b. The Code of Federal Regulations states that only physicians can be designated as AMEs
c. The American Medical Association does not permit physician extenders to perform physical examinations
d. Insurance companies will not reimburse for examinations performed by non-physicians
B. The Code of Federal Regulations states that only physicians can be designated as AMEs
{cf. AME Guide, General Information, para. 1}
What must a regional flight surgeon consider when deciding whether an AME should be made a Senior AME?
a. The AME has at least 3 years of experience as an AME
b. There is a need for a Senior AME in the geographic region where the AME is practicing
c. The AME has an excellent performance record
d. ALL of the above
d. ALL of the above
Which physical examination(s) are NOT required for an FAA physical?
a. Eyes and ears
b. Heart and lungs
c. Breast and digital rectal
d. None of the above
C. Breast examination: The breast examination is performed only at the applicant’s option or if indicated by specific history or physical findings. {AME Guide, Item 35} DigitalRectalExamination:Thisexaminationisperformedonlyattheapplicant’soption unless indicated by specific history or physical findings. {AME Guide, Item 39}
14 CFR, Part 67 defines those FAA officials who must take action on an issued medical certificate for it to not be considered affirmed. What is the time period within which the official must act to avoid cumbersome legal action to deny or suspend a certificate?
a. 2 weeks
b. 30 days
c. 60 days
d. There is NO time limit
C. A medical certificate issued by an AME is considered to be affirmed as issued unless, within 60 days after date of issuance (date of examination), it is reversed by the Federal Air Surgeon, a RFS, or the Manager, AMCD. However, if the FAA requests additional information from the applicant within 60 days after the issuance, the above-named officials have 60 days after receipt of the additional information to reverse the issuance.
{AME Guide, General Information, para. 2}
What is required for a special issuance for obstructive sleep apnea?
a. Maintenance of Wakefulness Test
b. Evidence of definitive treatment with a current status report from treating physicians
c. A pilot’s compliance statement confirming no excessive daytime sleepiness
d. Both B and C
D. Signed Airman Compliance with Treatment Sheet or equivalent from the airman attesting to absence of OSA symptoms and continued daily use of prescribed therapy; and A current status report from the treating physician indicating that OSA treatment is still effective.
{AME Guide, AASI for Sleep Apnea/Obstructive Sleep Apnea}
Which of the following is NOT acceptable distant vision for a Class I or Class II Aviation Medical Certificate:
a. 20/20 in each eye separately, without correction
b. 20/50 in each eye separately, without correction
c. 20/50 in each eye separately, corrected to 20/20
d. 20/100 in each eye separately, corrected to 20/20
B. Class I & II require 20/20 or better in each eye separately, with or without correction.
Class III requires 20/40 or better in each eye separately, with or without correction.
{AME Guide, Synopsis of Medical Standards}
Any class medical certificate can be issued to an individual with an implantable defibrillator.
a. True
b. False
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}
Which of the following does NOT qualify as a CACI (Conditions AME Can Issue):
a. Arthritis
b. Bladder Cancer
c. Retained Kidney Stone
d. Colon CA
e. Glaucoma
f. Diabetes
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}
What is the inclination of the International Space Station?
a. 28 degrees.
b. 42.8 degrees.
c. 51.6 degrees.
d. 62 degrees.
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}
The purpose of the International Health Regulations [IHR (2005)] is to prevent international disease spread by early detection of, and effective response to, events that pose a risk to public health. Concerning international civil aviation, compliance with the IHR is:
A. The responsibility of all international air carriers.
B. Mandatory for all Member States of the World Health Organization (WHO).
C. The responsibility of the International Civil Aviation Organization (ICAO) as stated in Annex 9 to the convention on International Civil Aviation.
D. Optional and voluntary, but ICAO Contracting States and WHO Member States, Associate States and other States bound by the IHR (2005) shall comply with the regulations unless they have indicated to ICAO and WHO that their position is not to be bound by the IHR, or to be bound with reservations only.
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}
As of 1 Jan 2016, FAA rules governing transportation of patients by air:
A. Do not address patient care recommendations.
B. Require a medical attendant who has met NREMT Basic Emergency Medical Technician requirements, and is knowledgeable in aviation physiology.
C. Require NREMT examination and certification as an EMT-Paramedic, with additional training in aviation physiology.
D. Require oxygen available for all patients, and for all crew members for flights above 12,500 ft. over 30 minutes, or all flights above 14,000 ft.
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}
When operating an unpressurized aircraft, supplemental oxygen by mask may be necessary to prevent hypoxia in flight crew and passengers. According to Federal Aviation Regulations, above what altitude is supplemental oxygen required to be provided for each occupant of the aircraft?
A. 10,000 feet (MSL
B. 12,500 feet (MSL)
C. 14,000 feet (MSL)
D. 15,000 feet (MSL)
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.
Regarding airport mass casualty planning, all of the following are required EXCEPT:
A. A certified airport must have one review of the emergency plan with the involved parties every 3 years.
B. JCAHO requires hospitals to test the hospital disaster plan twice a year.
C. Most disaster plans use the Incident Command System (ICS) as a pattern for command and control.
D. Emergency medical services are usually under the control of the Chief of Operations in the ICS system.
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.
When determining to what extent individuals are suited to air traffic control work, which of the following factors is not considered predictive.
A. Age
B. college grade point average
C. overall level of adjustment
D. previous air traffic control experience
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.
In a survey of US Air Carrier accidents for the period 1983-2000, the incidence of fatalities was determined. Which of the following probability statements is INCORRECT?
A. Of all accidents, only one in 20 passengers was killed.
B. Of serious accidents, more than half the passengers survived.
C. Of serious accidents, over 80% of passengers were killed.
D. Of serious survivable accidents, more than 75% of passengers survive.
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.
Regarding the risk of deep vein thrombosis (DVT) in commercial air travel, which of the following is most correct.
A. The risk of DVT has been shown to be elevated in commercial air travel compared to other forms of transportation (the “Economy Class Syndrome”).
B. Dehydration and the relative hypoxia of the cabin altitude contribute to DVT risk.
C. Aspirin is a prudent recommendation for DVT prophylaxis in air travelers.
D. Low-molecular weight heparin may be indicated for passengers with risk factors for DVT.
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.
What percent of fatally injured aircraft occupants of structurally survivable general aviation accidents have demonstrated head trauma?
A. 10%
B. 30%
C. 50%
D. 80%
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.
Many factors exist which favorably influence the ability of the human to withstand larger decelerative forces occurring during a crash. Select the best answer:
A. Crash forces are better tolerated in the forward-to-backward direction (G×).
B. Some crash forces can be attenuated by providing resilient cushions around the occupant.
C. Man can withstand greater magnitudes of deceleration if they are applied at faster rates.
D. It is possible to increase the magnitude tolerated by increasing the duration of the applied force.
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.
Which cancer causes the most deaths in the United States annually?
A. Breast cancer
B. Colon cancer
C. Lung cancer
D. Prostate cancer
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}
A 55-year-old man has a 20-pack-year history of smoking. He quit smoking 5 years ago. He currently does not complain of any symptoms. The US Preventive Services Task Force recommends which of the following screening services for this man?
A) Annual chest CT scan
B) Annual chest x-ray
C) Both an annual sputum cytology and an annual chest X-ray
D) No screening for asymptomatic individuals
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}
Annual breast self-examinations to screen for breast cancer:
A) Increase the number of breast biopsies performed.
B) Reduce all-cause mortality in women.
C) Reduce mortality due to breast cancer in women.
D) Reduce the use of mammography.
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.}
Routine aspirin is recommended by the U.S. Preventive Services Task Force for prevention of cardiovascular disease in which of the following groups?
A) Men and women ages 40 to 59 years with a 10% or greater 10-year cardiovascular disease risk.
B) Men and women ages 50 to 69 years with a 10% or greater 10-year cardiovascular disease risk.
C) Men ages 40 to 59 years and women ages 50 to 69 years with a 10% or greater 10-year cardiovascular disease risk.
D) No specific group overall. Decision to use low-dose aspirin should be made on an individual basis.
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}
A 58 year-old woman has a normal screening mammogram at her appointment today. She has no family history of breast cancer and no symptoms. According to the U.S. Preventive Services Task Force, her next mammogram would be due in:
A) 6 months.
B) 1 year.
C) 2 years.
D) 3 years.
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}
According to the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure VII (JNC VII) recommendations, the goal treatment blood pressure for patients with no co-morbidities is less than:
A) 120/80
B) 130/80
C) 140/80
D) 140/90
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}
A 52 year-old woman presents for preventive care. She had a total hysterectomy 4 years prior for benign disease. All of her Pap smears have been normal in the past and she has been in a monogamous sexual relationship for the past 20 years. Which of the following is the most appropriate recommendation?
A) A Pap smear every 3 years until the age of 65 years.
B) A Pap smear every year until the age of 65 years.
C) Annual Pap smears if she gets a new sexual partner, otherwise Pap smears are not needed.
D) Further Pap smears are not indicated.
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}
The U.S. Preventive Services Task Force recommends cholesterol screening for all of the following groups EXCEPT:
A) Men above the age of 20 years who are at increased risk for coronary heart disease.
B) Men above the age of 35 years.
C) Women above the age of 20 years who are at increased risk for coronary heart disease.
D) Women above the age of 45 years.
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.}
Which of the following is one of the factors considered by the U.S. Preventive Services Task Force making screening recommendations?
A) Burden of suffering from the target condition
B) Cost of screening tests
C) Cost effectiveness of screening tests
D) Insurance coverage for screening tests
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.
Which of the following statements about genetic testing for screening is correct?
A) Genetic tests can divulge information about family members not consenting for testing.
B) Genetic tests cannot be used for population screening.
C) History taking and counseling by geneticists and primary care clinicians are the same.
D) The U.S. Preventive Services Task Force recommends ordering BRCA testing for women whose family history suggests they are at increased risk for breast cancer.
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.
Which of the following is a risk factor for prostate cancer?
A) Age > 40 years
B) Family history of prostate cancer
C) Uncontrolled diabetes
D) Urinary hesitancy and nocturia
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}
A 65 year-old man with a 50 pack-year history of smoking, who quit 5 years ago, is overweight and is taking cholesterol medication and aspirin, comes in for an annual exam. His blood pressure today is 130/80 and he is not taking antihypertensive medication. Which of the following screening tests would be appropriate for this patient at the current visit according to the U.S. Preventive Services Task Force?
A) Dual energy x-ray absorptiometry
B) Fasting glucose
C) Ultrasound of abdominal aorta
D) Ultrasound of carotid arteries
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}
A 65 year-old woman who has a 20 pack-year history of smoking is here for an annual exam. Her blood pressure is 126/78 and she is currently on no medications. Which of the following screening tests would be appropriate for this patient at the current visit according to the U.S. Preventive Services Task Force?
A) Dual energy x-ray absorptiometry
B) Fasting glucose
C) Ultrasound of abdominal aorta
D) Ultrasound of carotid arteries
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.
A 20 year-old female athlete comes to your office for an annual exam. Her body mass index is 21 kg/m2
and she has no known family history of cardiovascular disease or cancer. Which of the following screening tests would be recommended at this visit by the USPSTF based on an “A” recommendation for this age group?
A) Blood pressure
B) Cholesterol
C) Fasting glucose
D) Thyroid stimulating hormone (TSH)
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}
Screening for which of the following cancers currently has a “D” recommendation from the U.S. Preventive Services Task Force in persons younger than 75 years?
A) Breast cancer with clinical breast examination
B) Prostate cancer
C) Skin cancer
D) Testicular cancer
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}
According to the World Health Organization (WHO), in children under age 5 years (except the neonatal period), acute respiratory disease is the greatest cause of death. What is the next most common global cause of death in this group?
A) Diarrheal diseases
B) HIV/AIDS
C) Injuries
D) Malaria
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}
For which serologic status would a mother be most likely to transmit Hepatitis B vertically to her infant at birth?
A) Hepatitis B surface antigen positive
B) Hepatitis B surface and “e” antigen positive
C) Hepatitis B surface antibody positive
D) Hepatitis B core antibody and surface antibody positive
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
A 61-year old man comes to your travel clinic to get a yellow fever vaccination in anticipation of a cruise up the Amazon River leaving in 2 months. Two weeks previously, he went to his primary care provider and got the first dose of hepatitis A, parenteral typhoid, and a routine vaccination against shingles. Assuming he is otherwise healthy and accepts the age-associated risk of vaccination, what would you recommend?
A) Defer yellow fever vaccination for at least another two weeks.
B) Give yellow fever vaccine this visit.
C) Give yellow fever vaccine this visit with the second dose of Hepatitis A.
D) Wait to receive yellow fever vaccination on arrival in Brazil.
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.
A young man develops painful urination after a “one night stand”. Examination confirms a purulent urethral discharge, but gram stain isn’t available. Pending result of nucleic acid amplification tests, what is the best antibiotic choice to adequately cover the most likely causes if you decide to treat empirically this visit?
A) Ceftriaxone 125 mg injection
B) Azithromycin 2 gram orally once
C) Levofloxacin 500 mg daily for 7 days
D) Doxycycline 100 mg twice daily for 7 days
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.
An interferon-gamma release assay (IGRA) test for tuberculosis would be preferred to a tuberculin skin test (TST) to diagnose tuberculosis infection in:
A) A new hospital employee who has never been tested for tuberculosis.
B) A TB contact investigation involving a child under age 5 years.
C) A severe rheumatoid arthritis patient just admitted to long term care
D) A recent adult immigrant who had BCG vaccination as a child.
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.
Which of the following potential biological warfare category “A” agents has been described to be transmitted solely human to human and not through some animal or insect vector?
A) Marburg virus
B) Tularemia
C) Plague
D) Smallpox
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.
A researcher administers 100 mg of a drug to a group of mice. Half of the mice are found dead 3 days later. The researcher concludes that the:
A) LOEL for this drug is 50 mg.
B) LD50 for this drug is 50 mg.
C) LD50 for this drug is 100 mg.
D) NOAEL for this drug is 100 mg.
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.
The stages of carcinogenesis in order are:
A) Promotion, initiation, progression
B) Progression, promotion, initiation
C) Initiation, promotion, progression
D) Initiation, progression, promotion
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
Select the correctly matched pair of toxicants and corresponding health effects:
A) Lead-sensorimotor neuropathy
B) Mercury-lung cancer
C) Asbestos-leukemia
D) Hepatitis A-chronic liver disease
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.
A level 7.0 earthquake strikes a developing country. There are news reports of widespread destruction and many displaced persons. The most appropriate FIRST step in disaster response is:
A) Send trucks with bottled water and canned goods to the area.
B) Conduct a needs assessment of the affected area.
C) Deploy military troops to provide safety and prevent looting.
D) Drop supply kits with food and bottled water to affected areas using helicopters.
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.
A group of workers are exposed to a radiation dose of 5 Sieverts (500 REM). The most likely health effects within the next 24 hours would be:
A) Coma and death
B) Hemorrhage
C) Nausea and vomiting
D) Cough and fever
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}
A group of healthy adults are planning a trip to sub-saharan Africa. The most appropriate antimalarial agent for malaria prophylaxis for this group is:
A) Chloroquine
B) Malarone
C) Ciprofloxacin
D) Azithromycin
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}
A construction worker who is employed by a large company which has thousands of employees falls off scaffolding and falls to his death. His employer must report this event within:
A) 8 hours
B) 24 hours
C) 1 week
D) 1 month
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.}
Which of the following vaccines are required for travelers to specified areas?
A) Hepatitis A and Tetanus
B) Polio
C) Measles, mumps and rubella
D) Yellow Fever and Meningococcal
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.
Which of the following surveys includes physical assessment of respondents?
A) Behavioral Risk Factor Surveillance System
B) National Health and Nutrition Examination Survey
C) National Survey of Drug Use and Health
D) Youth Risk Behavior Survey
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.
Which of the following best describes the factors involved in the Health Belief Model?
A) Perceived barriers to and benefits of action
B) Perceived barriers to and benefits of action, self-efficacy, and cues to action
C) Perceived barriers to action, self-efficacy, and cues to action
D) Perceived self-efficacy and cues to action
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).
What percent of the National Survey of Drug Use and Health respondents are current binge drinkers?
A) 7%
B) 23%
C) 44%
D) 57%
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.
All of the following have been shown to be effective strategies for reducing risky alcohol drinking EXCEPT:
A) Alcohol pricing and taxation
B) Controls on media advertising
C) Health warning labels on packaging of alcohol products
D) Penalties for drinking and driving
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}
Which of the following is NOT routinely addressed in the Behavioral Risk Factor Surveillance System (BRFSS)?
A) Blood stool testing
B) Fruits and vegetable intake
C) Health insurance
D) Substance and marijuana use
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}
Which of the following is true about treatment of mental disorders?
A) Pharmacological treatment is significantly better than psychological treatment.
B) Psychological treatment is significantly better than pharmacological treatment.
C) Pharmacological and psychological treatments are equally effective and response is somewhat better when combined.
D) Pharmacological and psychological treatments are equally effective and response is not significantly better when combined.
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/}
Which of the following models of health behavior includes belief about whether influential others approve or disapprove of the behavioral change being considered?
A) Health Belief Model
B) Social Learning Theory
C) Theory of Reasoned Action
D) Transtheoretical Model
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.
In applying the Stages of Change Model to smoking cessation, which of the following actions would be most appropriate for smokers in the preparation phase?
A) Discussing health risks of smoking
B) Personalizing health risks/benefits
C) Prescribing medication
D) Setting a quit date
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.
The U.S. Preventive Services Task Force recommends behavioral counseling for which of the following?
A) Alcohol misuse
B) Healthy diet in average risk adults
C) Physical activity
D) Preventing skin cancer
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}
Which of the following is NOT a part of Rothman’s typology of community organization?
A) Locality Development
B) Locus of Control
C) Social Action
D) Social Planning
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.
What percentage of Americans will meet the criteria for a DSM-IV disorder during their lifetime?
A) 10%
B) 25%
C) 50%
D) 75%
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.}
Which of the following DSM-IV disorders has the highest lifetime prevalence in the United States?
A) Anxiety Disorders
B) Depression/Mood Disorders
C) Impulse Control Disorders
D) Substance Abuse Disorders
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.}
In the 1980’s, the legal drinking age was raised to 21 years after more than a decade of 18 years as the legal drinking age in most states in the United States. This increase in the legal drinking age was accompanied by which of the following changes in the rate of alcohol-related motor vehicle crashes?
A) 15% decrease in overall rate.
B) 15% decrease in rate among persons under 21 years of age.
C) 15% increase in rate among persons under 21 years of age.
D) No significant change in the rate.
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.}
Approximately what percent of motor vehicle crashes in the United States are alcohol-related (driver or non-occupant, e.g. pedestrian)?
A) 10%
B) 20%
C) 40%
D) 60%
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}
Which of the following groups has the highest rate of suicide in the United States?
A) Non-Hispanic white females ages 15-19 years.
B) Non-Hispanic white males ages 20-24 years.
C) Non-Hispanic black males ages 20-24 years.
D) Non-Hispanic white males ages 85 years and older.
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}
You have been seeing two patients of approximately the same age for whom you are concerned about the possibility of suicide, a female and a male. Which of the following is NOT true regarding the differences in suicide by gender in the United States?
A) The male patient is 4 times more likely to commit suicide.
B) The male patient is more likely to make unsuccessful attempts.
C) The male patient is more likely to use firearms.
D) The female patient is more likely to use poison.
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}
The majority of local health departments are under the jurisdiction of what authority?
A) City
B) County
C) Multi-county
D) State
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}
Trends in the distribution of patient care physicians by practice type from 1996 to 2005 show that fewer physicians are:
A) Joining solo or two-physician practices.
B) Joining physician practices with 6 to 50 physicians.
C) Joining medical school faculties.
D) Working for hospitals.
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.
What part of Medicare covers the cost of hospital services?
A) Part A
B) Part B
C) Part C
D) Part D
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.
Looking at trends in the distribution of national health expenditures, which type of service showed the greatest growth from 1997 to 2007?
A) Hospital Care
B) Physician and Clinical Services
C) Prescription Drugs
D) Nursing Home Care
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/}
A physician orders a thyroid stimulating hormone (TSH) test on a patient. The test result comes back indicating the TSH is elevated. No action is taken and the patient develops complications as a result of hypothyroidism. Which class of medical error does this represent?
A) Diagnostic Error
B) Equipment Failure
C) Translation Error
D) Misinterpretation of Medical Orders
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}
Which of the following health risks has the highest association with absenteeism at work?
A) Elevated body mass index
B) Hypertension
C) Hypercholesterolemia
D) Low physical activity level
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.
Carpal tunnel syndrome is characterized by which of the following?
A) Hypothenar muscle atrophy in severe or longstanding cases
B) Nocturnal paresthesias
C) Numbness in the 4th and 5th fingers
D) Reduced sensory latency in the median and ipsilateral ulnar nerves
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.
Egg shell calcification on a chest X-ray is most likely to be seen in which occupational lung disease?
A) Asbestosis
B) Chronic beryllium disease
C) Coal worker’s pneumoconiosis
D) Silicosis
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.
The cause of most cases of occupational low back pain is:
A) Facet joint arthropathy
B) Herniated disc
C) Sacroiliac (SI) joint dysfunction
D) Unknown
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.
Which agency promulgates recommended exposure limits (REL’s)?
A) American Conference of Governmental Industrial Hygienists (ACGIH)
B) Environmental Protection Agency (EPA)
C) National Institute of Occupational Safety and Health (NIOSH)
D) Occupational Safety and Health Administration (OSHA)
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.
The increased risk of lung cancer in the Colorado Plateau uranium miners is the result of excess exposure to:
A) Alpha radiation
B) Asbestos contamination
C) Beta radiation
D) Surveillance X-rays
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.
A researcher wants to examine the effect of a physical activity intervention on weight among grade school children. Twenty elementary schools are randomly assigned to either the intervention or control group. The researcher decides to compare the mean weight change between the 300 students in the intervention group overall and 300 students in the control group overall. Which statistical test should be used to analyze these data?
A) Analysis of variance (ANOVA)
B) Paired t–test
C) Two-sample t-test
D) Wilcoxon signed rank test
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}
A researcher wants to examine the effect of a physical activity intervention on weight among grade school children. Twenty elementary schools are randomly assigned to either the intervention or control group. The researcher decides to compare the mean weight change between the 300 students in the intervention group overall and 300 students in the control group overall. This study used which type of randomization?
A) Cluster
B) Simple
C) Stratified
D) Systematic
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}
In an RCT of surgical treatment versus medical treatment of children with recurrent throat infections, children in both groups had fewer episodes of throat infection in the year after treatment than in the year before treatment. To what could this finding be attributed?
A. Allocation bias
B. Lack of intention to treat analysis
C. Failure to control for variables
D. Regression toward the mean
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}
The mean LDL cholesterol level of a group of 100 patients is 130 with a standard deviation of 10. Which of the following represents an approximate 95% confidence interval of the mean?
A) 110, 150
B) 120, 140
C) 124, 136
D) 128, 132
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}
A research team is studying whether proximity to fast food outlets is associated with body mass index (BMI). The relationship between the distance from home to the nearest fast food outlet and the BMI of 25 subjects expressed as a graph shows that the value on the y axis (BMI) decreases as the value on the x axis (distance) increases and has an R^2 of 0.64. What is the correlation coefficient of this relationship?
A) 0.64
B) -0.64
C) 0.80
D) -0.80
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}
A research team is studying whether proximity to fast food outlets is associated with body mass index (BMI). The relationship between the distance from home to the nearest fast food outlet and the BMI of 25 subjects expressed as a graph shows that the value on the y axis (BMI) decreases as the value on the x axis (distance) increases and has an R^2 of 0.64. What percent of variation in BMI does distance to the nearest fast food outlet explain?
A) 8%
B) 36%
C) 64%
D) 80%
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}
A research team is studying whether proximity to fast food outlets is associated with body mass index (BMI). The relationship between the distance from home to the nearest fast food outlet and the BMI of 25 subjects expressed as a graph shows that the value on the y axis (BMI) decreases as the value on the x axis (distance) increases and has an R^2 of 0.64. What is the most valid conclusion that can be drawn?
A) Living near fast food outlets and having a higher BMI are likely to occur together, but the relationship may not be causal.
B) People living close to fast food outlets are likely to have higher BMIs because they eat at these outlets more often.
C) People living close to fast food outlets are likely to have higher BMIs because they are less more likely to eat at fast food outlets.
D) People with higher BMIs have other characteristics that make them more likely to have fast food outlets in their neighborhoods.
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}
Serum ferritin was found to have the following distribution in a study of 10,000 healthy men:
-
- -
- - - -
- - - - - - - -
- - - - - - - - - - - - - - -
Which of the following is the most appropriate measure of central tendency for serum ferritin in this distribution?
A) Arithmetic mean
B) Geometric mean
C) Mode
D) Standard deviation
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}
Serum ferritin was found to have the following distribution in a study of 10,000 healthy men:
-
- -
- - - -
- - - - - - - -
- - - - - - - - - - - - - - -
Comparing the values of the arithmetic mean and the median of the distribution would reveal that the arithmetic mean:
A) Is greater than the median.
B) Is less than the median.
C) Is the same as the median.
D) Cannot be determined.
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.
Serum ferritin was found to have the following distribution in a study of 10,000 healthy men:
-
- -
- - - -
- - - - - - - -
- - - - - - - - - - - - - - -
The distribution of serum ferritin in women is found to have a similar shape to that of men, which is presented in the frequency distribution above. Which of the following would be the most appropriate test to determine whether serum ferritin levels were significantly higher in a sample of 20 men compared with a sample of 20 women from this study?
A) Kruskal Wallis test
B) Paired t-test
C) Two-sample t-test
D) Wilcoxon rank sum test
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}
An analysis of variance (ANOVA) was performed to compare the mean systolic blood pressure in 4 different patient groups with 41 subjects in each group. The critical value for the F-statistic at α = .05 is 8.54. The F-statistic was calculated to be 12.3. Using p<.05 to define statistical significance, what conclusions can be made from the ANOVA?
A) None of the means of the 4 groups are statistically significantly different than the mean of any other group.
B) At least one of the means is statistically significantly different than all of the other means.
C) At least one of the means is statistically significantly different than one other mean.
D) The means of the 2 groups with the largest means are statistically significantly different than the means of the 2 groups with the smallest means.
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}
You have conducted a study on the effect of zinc on incidence of a cold within 2 weeks of inculation with rhinovirus. Subjects are randomized to receive zinc or placebo and then are inoculated with rhinovirus. At the end of the study period, you have the following results:
Colds No Colds Zinc 30 70 Placebo 60 40
What is the correct comparison for determining whether zinc successfully prevents colds?
A) 15% vs. 30%
B) 30% vs. 60%
C) 30% vs. 70%
D) 50% vs. 65%
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.
You have conducted a study on the effect of zinc on incidence of a cold within 2 weeks of inculation with rhinovirus. Subjects are randomized to receive zinc or placebo and then are inoculated with rhinovirus. At the end of the study period, you have the following results:
Colds No Colds Zinc 30 70 Placebo 60 40
The appropriate test of significance for the data as presented above would be:
A) Chi square
B) Log rank
C) Kappa
D) Two-sample t-test
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}
You are studying the effects of aspirin desensitization on symptom severity in patients with Aspirin Exacerbated Respiratory Disease. You obtain a symptom severity score, rated 0 (no symptoms) to 5 (severe symptoms), from each of 15 subjects prior to desensitization and 1 month after completion of desensitization. The most appropriate analytic test to determine whether sensitization had a statistically significant effect on symptom severity in this study is:
A) ANOVA
B) Paired t-test
C) Wilcoxon rank sum
D) Wilcoxon signed rank
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}
A journal article you are reading states “We hypothesized that statins are associated with lower risk of lymphoma based on in vitro and clinical studies.” Given that the measure of association in this longitudinal study is relative risk (RR_Statins for patients who are taking statins and RR_NoStatins for patients who have never taken statins), what is the null hypothesis of this study?
A) RR_Statins ≤ RR_NoStatins
B) RR_Statins < RR_NoStatins
C) RR_Statins = RR_NoStatins
D) RR_Statins ≥ RR_NoStatins
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}
You are studying the effect of a new vaccine on the incidence of malaria in 2,000 malaria-naive subjects. 1,000 subjects were randomly assigned to receive the vaccine and 1,000 were randomly assigned to receive a placebo. All subjects were followed for 1 year. At the end of the trial, you find that 20 new cases of malaria occurred in the vaccine group and 40 new cases occurred in the placebo group. You also find that the average censored time was 40 weeks in the vaccine group and 52 weeks in the placebo group. Which of the following can be concluded from these data?
A) New cases of malaria occurred sooner on average in the vaccine group compared with the placebo group.
B) New cases of malaria occurred later on average in the vaccine group compared with the placebo group.
C) More subjects dropped out of the vaccine group compared with the placebo group.
D) More subjects dropped out of the placebo group compared with the vaccine group.
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.
A company could receive a fine for exposing employees inside an industrial facility to a hazardous substance from the:
A) American Industrial Hygiene Association.
B) Environmental Protection Agency.
C) National Institute for Occupational Safety and Health.
D) Occupational Safety and Health Administration
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
A 40-year-old railroad conductor with the following audiogram results (values in decibels (dB)) likely is experiencing which type of hearing loss?
250Hz 500Hz 1000Hz 2000Hz 4000Hz 8000Hz Left 0. 5. 10. 15. 30. 20 Right. 5. 5. 15. 25. 35. 30
A) Conductive
B) Congenital
C) Sensorineural
D) Mixed conductive and sensorineural
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.
A supervisor contacts you for advice regarding an employee who has seemed increasingly confused throughout the afternoon. His balance is now poor, he is slow to respond to questions, and his supervisor remarks that the 20-year-old man does not appear to be sweating, despite working a heavy construction job outside all day in 95 degree F heat. The employee began employment at this job about a week ago. The employee has no known medical conditions. Appropriate advice to the supervisor at this time would be to:
A) Initiate oral rehydration in a cool place with water.
B) Initiate oral rehydration in a cool place with a salt-containing oral rehydration mixture.
C) Transport the employee to clinic for in-person evaluation and possible IV fluid resuscitation.
D) Transport the employee immediately to the nearest emergency department for additional evaluation and treatment.
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.
Shift workers tolerate shift changes better if they:
A) Work longer shifts.
B) Start day shifts early in the morning.
C) Rotate from day to evening to night shift.
D) Minimize days off between shift changes.
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.
Which of the following is NOT a method for controlling for confounding?
A) Matching by a possible confounding factor
B) Multivariate statistical adjustment
C) Randomization in a trial
D) Using confidence intervals in preference to p values
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.
Heart disease incidence after 10 yr f/u
Polymorphism. No. Yes. Total
Present. 80. 20. 100
Absent. 9000. 1000. 10,000
Total. 9080. 1020. 10,100
Based on these data, what is the relative risk (RR) for heart disease associated with having this genetic polymorphism ?
A) 0.2
B) 1.1
C) 2.0
D) 5.0
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
You are interested in studying gender as a factor in outcomes after coronary artery bypass graft (CABG) procedures at University Hospital. Among 100 consecutive patients undergoing the procedure in 2003, you find that 60 were men and 40 were women. Among these 100 patients, there were 24 deaths over the 5 years after surgery. What is the risk ratio (RR) for death in 5 years following CABG procedures at University Hospital for women compared with men?
A) 0.67
B) 0.4
C) .096
D) The RR cannot be estimated from data given.
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.
You are considering a new screening program to identify people with diabetes mellitus using a standardized screening method. Which of the following factors would lead to the greatest variability in the positive predictive value of the screening test among different communities in the United States?
A) Different methods for treating diabetes in different communities
B) Different prevalences of diabetes in different communities
C) Different sensitivities of the test in different communities
D) Different specificities of the test in different communities
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.
You wish to use a self-administered questionnaire to screen for symptoms of Disease X in a community of 1000 people. The cost of administering the questionnaire is inexpensive ($2 per person screened). The sensitivity of the questionnaire is 90% and the specificity is 96%. The next step after a positive screening questionnaire is a diagnostic MRI, which costs $1000 per person. If the true prevalence of Disease X is 5% in the community to be screened, and if everyone were to take part in the screening program, what would be the total cost be for screening and diagnosis?
A) $2,000
B) $50,000
C) $85,000
D) $1,002,000
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.
You are collaborating with the orthopedic service of St. Joseph’s Hospital to assess outcomes after hip replacement surgery. In the most recent 5-year period you identified 600 patients undergoing hip replacement, of whom 100 were followed for one year, 200 for 2 years, 150 for 3 years, 100 for 4 years, and 50 for 5 years. There were 120 deaths identified in this time period. What is the death rate among the 600 patients who underwent hip replacement?
A) 20 per person-year
B) 24 per 100 person-years
C) 75 per 1000 person-years
D) 120 per 10,000 person-years
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.
You use a new blood test to screen for disease X in a group of members from a retirement community, and find that 65% survive for 5 years or more after diagnosis with disease X subsequent to this new screening test. The historic 5-year survival for this community and the 5-year survival reported for the entire state is only 34%. Which of the following is NOT a valid reason that could explain this improvement in 5-year survival?
A) Lead time bias
B) Length bias
C) Lower false positive rate of the new screening test compared with the old test
D) True benefit from screening
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.
You wish to study a new hypothesis that participation in sports activity is a protective factor for osteosarcoma. You design a study in which sports activity is ascertained by questionnaire. The incidence of osteosarcoma is 1 per 100,000 per year. You determine you will need about 100 people with osteosarcoma for adequate statistical power. Which of the following study designs would be most efficient to test your hypothesis?
A) Case-control study
B) Cohort study
C) Cross-sectional survey
D) Randomized, controlled trial
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.
