Public Health (Epi, Stats, Ethics)

Question 1

A community health task force is promoting obesity awareness and education in the area. The task force studies epi data from the county health dept, showing that prevelance of obesity is 3 times higher in a cluster of 5 ZIP codes than avg. Task force elects a leader for assistance in understanding pattern. What should be performed first to understand the etiology of the disparity in obesity prevalnce?

Answer 1

cross-sectional analysis of demographic attributes & health behaviors across community ZIP codes.

> > since obesity is largely multifactorial, cross-sectional analysis of demo/behavior data is best to determine “snapshot” of multiple risk factors in single instance–can help direct further research hypotheses

**NOT qualitative survey assessing obesity-related beliefs, attitudes, and knowledge of representative community sample» qualitative surveys are useful for generating broad hypothesis for a community epi pattern; it obesity trends

Question 2

36yr F w/ controlled asthma and hypothyroidism comes for f/u. She’s been a pt for 8yrs, discusses her recent divorce with you…pt asks you on a date. You find the pt attractive, and would like to accept the invitation. What is the appropriate response?

Answer 2

decline invitation, explaining that going on date would be unethical.

> > potential exploitation and/or interference w/ doc’s objective clinical judgement. Ethically acceptable if the doc-pt relationship is terminated well before initiating relationship.
it’s also inappropriate to suggest termination of doc-pt relationship solely for dating, and pt should not be forced to choose btw physician be tx provider or romantic partner.

**answer is NOT decline invite, explain pt-doc relationship must be terminated before relationship.

Question 3

Data shows 400pts w/ normal distribution and a mean of 220mg/dL cholesterol level. SD of 10. How many patients would be expected to have serum cholesterol 240 or above?

Answer 3

10

> > 68-95-99.7% rule.
68 w/in 1 SD, 95 w/in 2SD, 99.7 w/in 3SD.

240 or greater is a +2SD point= 95% of graph, meaning that 5% of all individuals lie outside of that (1/2 below, 1/2 above)» 2.5% above* 400 total pt= 10

Question 4

You suspect intimate partner violence in pregnant patient. What is the most appropriate next step in management?

Answer 4

assess for immediate safety and give additional resources (domestic violence program) for long term safety planning

> > given the risk for maternal morbidity, homicide, and pregnancy complications, screening for IPV is required at initial prenatal visit, during each trimester, and postpartum. Some jurisdictions may also require mandatory reporting for IPV during pregnancy.

Question 5

80yr M into ER by son for SOB, weight loss, chronic cough. Large mass in R lung revealed a mass + pleural effusion. Pt has bronchoscopy w/ biopsy, +bronchogenic carcinoma. When phycisian initiates private discussion, the pt says ‘I prefer not to be told anything. You can discuss w/ my son. I trust his judgement.” The is patient is of sound mind, without mental illness. What is the most appropriate doc response?

Answer 5

“I understand that you don’t want to be told the results of the biopsy. I will share them with your son.”

> pt’s have the right to refuse to receive medical information. Pt expresses clear preference and capacity, must respect their autonomy. Some cultures also find it cruel/disrespectful to disclose serious illness to elders, and custom for family to make health decisions. Others believe that speaking about it makes it more terminal/final.

**not could you tell me why you got the bronch if you did not wish to know the results?= judgemental

Question 6

33yr F transferred to University from small community hospital for acute pyelonephritis w/ sepsis. PMH recurrent UTIs w/ urinary retention due to spinal cord child injury. Pt is febrile + lethargic. Only info given is on an illegible, handwritten note from the original hospital. Pt admitted to ICU w/ antibotics. Overnight, pt develops rash & requires vent for RDS. The following morning, a transcribed physician note from original hospital arrives indicating that pt is allergic to imipenem. When discussing events w/ patient and her family, which of the following statements is associated with reduced malpractice liability for the treating physician?

Answer 6

“I am so sorry an error led to your allergic reaction. I will do my best to help you through it.”

**not ‘we didn’t get the info in time, that’s why you were given the wrong antibiotic’> this puts blame on the other parties involved, often generating distrust toward all involved parties.
»most lawsuits are motivated by anger, distrust, or a feeling that clinician is not concerned for their well-being.

avoidance of lawsuit: openly acknowledge errors, express empathy, give apologizes where appropriate, avoid blaming others, allow adequate time for patients to ask questions.

Question 7

34yr M admitted to hospital w/ chest pain, ECG shows STEMI. Sample of blood is taken for pt to measure plasma levels for new test. Test repeated 3 times yields: 11.8, 9.2, 13.7 (ref: 4-14). What parameter is most likely low based on the results of new test?

Answer 7

precision/reliability
»repeated measures of the same sample yielded diff results

**accuracy/validity of test requires comparison to gold standard on same individual.

Question 8

46yr F admitted for elective hysterectomy for AUB. PMH DM, urinary incontinence, and smoked cigarettes for years, quit 5yrs ago. Indwelling cather is placed prior to surgery; surgery has no complications. Catheter is in place for the next 72hrs. Pt develops fever, suprapubic pain, flank tenderness. Urine culture grows EColi. What is the most important risk factor for pt infection?

Answer 8

duration of catheterization
»placement is the single most important risk factor for catheter-induced UTI, >48hrs significantly elevates biofilm formation risk.

> > female, DM increase risk of infection, but catheter has a higher attributable risk; smoking increases risk of bladder infection, but minimally for UTI. incontinence is not associated w/ significant increase risk (but it the most common reason for inappropriate indication of catheter placement)

Question 9

Researchers conducted randomized control trial to determine if a prophylaxis admin of drug X + prophylaxis drug Y undergoing vaginal del has effect on PPH. Randomly assigned 1g drug X (or placebo) w/ drug Y after del. The relative risk of PPH w/ drug X + drug Y is 0.80 (95% confidence 0.66-0.96). What is the most appropriate conclusion about the effect of drug X + drug Y on PPH the risk of PPH?

Answer 9

the risk of PPH is reduced by 20% when drug X is added prophylactically w/ drug Y.
(1-0.8=.2)

> > RR< 1 exposure dec dx risk
RR=1 (null) no effect
RR >1 exposure inc dx risk
**the confidence interval indicates the value is statically significant

**since we are looking at a RR this is probably a cohort study

Question 10

Pt comes in w/ signs of a yeast infection. The pt is sexually active w/ multiple partners. When asked about the genders of her sexual partners, the pt asks “why does it matter? I’m pretty sure it’s yeast infection, so I just need some meds”. What is the appropriate response?

Answer 10

“I routinely ask my patients about sexual partners b/c it helps me fully understand what their health needs are.”

> > normalize sexual history w/ language and demeanor, create a trusting space in which the patient can talk about the potentially uncomfortable and intimate topics. try not to make premature assumptions about comfortability w/ topic, just say it’s routine care.

Question 11

During 5yrs of f/u, 120/400 diabetics who had ACE- developed acute coronary event. Over the same time, 100/300 who had not taken ACE- experienced event. What is the relative risk of developing event in pts who were taking compared to those who weren’t?

Answer 11

RR= A/(A+B)/ (C/C+D)
denotes the risk of developing an outcome in exposed vs unexposed.

120/400 / 100/300 :)

Question 12

46yr F hospitalized for severe depression and fatigue. No other medical problems. Routine labs are ordered, and pt is started on antidepressants. After 1wk pt is discharged home w/ slightly improved condition to outpatient care. Pt remains severely fatigued and is unable to return to her job, forcing leave of absence. At her f/u appt 2wks later, review of hospital records show TSH level of 15.2 that was never addressed by inpatient care. Subsequent eval & thyroid tx result in rapid improvement. What is the appropriate category for this type of medical error?

Answer 12

preventable adverse effect»

doc’s failure to note and address abnormality is a preventable medical error, resulting in delayed diagnosis; if doc had adhered to standard of care, then error would’ve been prevented.

**malpractice is a legal determination in which tx provided is below accepted standard of practice, has resulted in injury/death to pt. it is not a category of medical error»but it is a consequence of many diff errors that result in harm

Question 13

what is a sentinel event error?

Answer 13

an unexpected occurrence involving death or serious physical/mental injury (inpatient suicide, death of full term infant, retained object)» required

**retained object would also be an example of preventable adverse event

Question 14

A study is conducted to eval the properties of a new test for diagnosing cancer. Study has 200 pts w/ cancer, 300 w/o cancer. Study shows test to be 80% sensitive, 70% specific. Based on this info, what is the approx # of FN test results?

Answer 14

40

> > use the sensitivity 0.80=TP/200, TP= 160. Then FN= (TP + FN)-TP= 200-160= 40. :)

Question 15

how is absolute risk reduction differ from relative risk reduction?

Answer 15

absolute is the risk difference, while the relative risk is the proportional risk difference.

> > ARR: control rate - treatment rate
RRR: ARR/control rate
RR: treatment rate/control rate (probability of an event occurring in the tx group compared to control group)

Question 16

Graphs shows changes in prevalence of DM2 w/in a given population (assume no migration, etc). The same population indicates no change (constant rate) of DM2 incidence. What is the most likely explanation for the changes denoted?

Answer 16

improved quality care (increased survival time), faster recovery, and increased mortality all affect changes in prevalence w/o a change in incidence.

**vaccine administration would dec both incidence/prev
**reduction of risk factors would dec both
**inc diagnostic sensitivity would inc both incidence/prevelance

Question 17

65yr M admitted to inpatient community hospital for worsening SOB. 40pk smoker, initially diagnosed w/ COPD exacerbation. CXR shows large hilar opacity, and CT confirms 4cm mass. During the process of obtaining consent for bronchoscopy, pt says ‘doc, please don’t tell me what they find, b/c if it’s cancer, I don’t want to know.’ What is the most appropriate response?

Answer 17

“I won’t share the results of procedure if that’s your preference, although I would like to understand how you came to that decision”

> not “I can’t imagine how stressful this is, but if the results do show cancer, it would be important for you to make a decision about tx” is premature, though it does show empathy/emotional reassurance, it is likely to pressure patient, and doesn’t respect their autonomy.

Question 18

28yr F G2P1 ER eval for vaginal bleeding. Pt had bright red spotting for 24hrs, but no contractions or leaky fluids. She is currently 31wks gestation based LMP, pt hasn’t had prenatal care. Her 1st pregnancy ended w/ uncomplicated spontaneous vaginal delivery at term. Uterus is non-tender, consistent w/ 31wks, u/s shows complete placenta previa. The findings are discussed w/ pt and she notes she would still like to have a vaginal delivery. Doc responds, unfortunately the only safe option is C-section. This response is an example of which ethical principle?

Answer 18

directive counseling» term applied to pt when there’s only 1 medically reasonable treatment option that is clearly superior evidence-based support, it is ethically appropriate to provide “directive counseling” in which only a single tx is recommended to pt.

**if the pt were to entirely refuse C-section, the doc would make sure pt understood he advised against it, and then have all the appropriate documentation.

Question 19

what is assisted decision-making?

Answer 19

when a family member/caregiver helps patient in making a medical decision (but doesn’t make the decision for the patient)

ie: pts that have intellectual disability or potentially reversable impaired in decision making capacity (flutc mental illness like schizophrenia)

Question 20

what is informed refusal

Answer 20

when the patient refuses a recommended medical tx following an informed consent discussion

Question 21

what is substituted judgement?

Answer 21

when the surrogate decision-maker makes a health care decision for an incapacitated patient based on surrogate’s knowledge of the patient’s wishes & values

Question 22

A prospective study evaluates the relationship btw regular antioxidant supplement use (vit C and E) and risk of stroke in healthy/physicially active men. Study compared stroke risk in those consuming antioxidants for more than 5yr, less than 5yrs, or never consumed. Results show men who consumed 5+yrs and 5-yrs w/ RR of .95, .75, respectively. The results were adjusted to account for baseline diff related to healthy behaviors and overall health. What factor most likely explains why the relative risk of stroke is lower w/ longer antioxidant use?

Answer 22

accumulation effect» the effect of exposure to risk factors may depend on the duration and intensity of exposure–> long-term exposure may be necessary well before an effect on disease process is clinically evident.

**lung cancer development after decades of smoking exposure

**this wouldn’t be selection bias as the individuals studied were already limited to healthy, active men, and then they adjusted for baseline differences in effort to reduce these bias.

Question 23

Doc is treating pt for depressed mood w/ psychtheraphy (based on previous eval). During it, pt asks ‘have you ever had depression or been in therapy?’. What is the best response to this patient?

Answer 23

“I am curious to understand what makes you ask that question”

> > pts often have various questions and may ask personal questions, it is important to not feel pressured into responding to personal/intrusive questions. most beneficial to maintain boundary by gently exploring why pt is asking» allows for deeper understanding of pt care/needs, and facilitates an easier trust relationship than just dismissal.

Question 24

65yr M concerned about cough after smoking. A recent cohort study reported that compared to heavy smokers, the RR of COPD for nonsmokers is 0.10 and moderate 0.40. The patient is a moderate smoker. What is the RR of COPD for moderate smokers compared to non-smokers?

Answer 24

.4/.1= 4= RR

RR is the measure of associate btw the exposure of risk factor and an outcome/disease commonly used in cohort studies. RR is equal to the risk of an outcome in exposed group (moderate) divided by risk of same outcome in nonexposed group (nonsmokers)

**RR for nonsmokers compared to heavy= .1; RR for moderate compared heavy is .4

Question 25

25yr F w/ inital eval of low mood. Pt moved to new apt 3 wks ago where she feels sad about leaving her dog, and is not sleeping well. Pt says pets are not allowed in building and that she would really benefit from a letter stating that she could have her dog live with her. Pt’s dog currently lives e/ parents a few miles away. What is the most appropriate response to these statements?

Answer 25

I can see you miss your dog very much; let’s start by talking about the mood symptoms you’ve been experiencing.

> > the best approach is to validate the pt concerns, and gather more info on which to base a decision. Asking the pt why she moved to apt that doesn’t allow dogs is likely to make her defensive and doesn’t result in a full positive assessment of patient thereafter. Writing a letter is up to the doc, but a full eval must be completed and documented.

Question 26

Zeracizumab is an experimental drug currently used in lung cancer treatments. Part of drug company evaluation is to analyze the 1yr survival after tx to determine the clinical efficacy of experimental tx. Based on results, what is the NNH for Zeracizumab tx?
Alive at 1 yr on Z 40; on chemo 51. Dead at 1yr on Z 60; on chemo 69.

Answer 26

number needed to harm= the number of people who must be treated before 1 additional adverse event occurs.

NNH= 1/absolute risk increase> calculate the adverse event rate (death) for experimental & control, then subtract to see diff for absolute risk increase, then calculate NNH.

40+60= 100 total in Z group
51+69=120 total in chemo

60/100=60% adverse rate Z
69/120=57.5% in chemo

60-57.5=2.5%, so there’s an absolute risk of 2.5% if Z tx

1/2.5%=40> 40pts need to be treated w/ Z before 1 addn person experiences adverse event (death in 1yr)

**note try to rearrange table w/ dead as +diseased, Z group as +risk and it makes more typical sense

Question 27

A resident is on her way to morning signout after an overnight shift, gets into a crowded elevator. The med student gets on and asks how her shift went. During convo the student carefully doesn’t mention pt name but asks “did the patient in R232 get her CT scan?” What is the most appropriate response to student?

Answer 27

let’s wait until morning signout to discuss all of the patients.

> > while it is accurate to say that discussing patients info in public is against hospital policy, admonishing student in public is not the best approach. Opt to defer the conversation to a more appropriate and private setting outside the elevator.

**discussing pt info even w/ name redacted is a violation of patient privacy. always discuss in private setting.

Question 28

A researcher selects a random sample of 100 men ages 18-24 and determines their mean cholesterol is 180, SD 40. They are in normal distribution. Based on info, approx 50% of men in sample will have what serum levels?

Answer 28

<180 (or >180).

mean=median=mode for normal distribution. using the 68-95-99.7 rule including 1SD breaks 50% mark. the only way to get ~50% is to go up or down only from mean.

Question 29

25yr F f/u on DM1. She takes long and short acting insulin and has good control, without diabetic complications. PMH also includes hypothyroidism, takes levo. Pt is now no longer eligible on parent’s insurance, and consults your advice for choosing plan. The pt has no disability and her main priority is low monthly payments. Her current job offers a variety of options for her to choose. What is the most appropriate option for this patient?

Answer 29

health maintenance organizations (HMO)» they are the most affordable

> pt w/o disability at her age doesn’t qualify for medicare (also no CKD for diabetic concerns yet).
w/ job we cannot assume pt is at low income/disadvantaged.
PPO plans are the most costly, but generally provide the most benefit for pts overall
POS plans are similar to HMO but have higher premiums, and significant costs if out network

Question 30

Reserchers conducted a randomized controlled trial to assess the effectiveness of a new drug. 75 pt received new drug + original tx, 75 pt received placebo + orignal tx. Results show 6 in new drug developed skin reaction, compared to 9 in placebo group. What is the relative risk reduction for skin reaction among pt in new drug group?

Answer 30

RRR measures how much a given tx reduces the risk of an unfavorable outcome relative to the control group.

> > 6/75= 8% new
9/75=12% placebo

RRR= 1-RR= 1-8/12=33%

Question 31

67yr M in ED w/ AMS. Was having dinner w/ daughter and then confused and slumped over. PMH AFib+ on anticoagulants. Widowed, lives w/ daughter. Pt is obtunded and unable to follow commands. Pupils midsized, unresponsive to light. Physician notes intubation is necessary at this time to protect airway, and asks for consent from son/daughter at beside. They tell physician that the patient doesn’t have advance directive, unsure how to proceed. What is the most appropriate next step in decision making for patient?

Answer 31

ask them both to make a decision based on what they think the patient would have wanted if he were able to make decision» ‘substituted judgment standard’

**which is not the same as they decide based on what they think is in the best interest of the patient. if the surrogates cannot determine what the patient would have chosen, only then should the decision be made based on what they think is best interest/what most people would want.

Question 32

46yr M in ED w/ STEMI. PMH cocaine, alcohol abuse, no cardiac disease. Undergoes emergent cardiac cath, and transferred to PACU. The physician is approached by distraught woman who says she’s the wife, and asks about the condition. “I am so worried, please tell me if my husband is okay”. What is the most appropriate response?

Answer 32

tell the woman pt is stable, but can’t discuss further until pt has given permission.

> > telling her pt is stable (instead of unable to say anything) limits the emotional harm to the pt by those who are likely to be family about the pt’s condition. if given permission later, doc should ask if sensitive details be omitted (ie the MI due to cocaine use that pt didn’t want revealed)

Question 33

74yr F in ED for confusion, w/ daughter who lives w/ her. Pt was diagnosed w/ aplastic anemia 1yr ago. Her condition reponded poorly and required many blood transfusions. Pt is alert & oriented to person only; unable to response to questions. CBC shows severe pancytopenia. Advanced directive of 9months ago show friend as health proxy, and she states pt didn’t want any more transfusions. But pt’s daughter insists that at dinner last week pt stated she wanted everything possible to prolong her life. In deciding whether to perform transfusion, what is the highest priority for doc to consider?

Answer 33

the friend’s instructions

> > since the pt elected the friend as healthy proxy, they take legal priority over all other decision makers to facilitate/respect pt’s informed decision making. although the reported change warrants further investigation w/ proxy, the established proxy remains the highest priority decision maker. All risks/benefits should be discussed w/ proxy but since this specific case had been discussed, it’s a closed deal.