Board Review Questions

Interactive Question Session

Bashar Hasan, M.D.

Question 1

A 70-year-old man is brought to the emergency department by ambulance after his neighbor found him confused and feverish at home. The patient has diabetes mellitus; on arrival, finger-stick glucose is >400 mg/dL. Temperature is 39.5 C (103.1 F), blood pressure is 90/60 mm Hg, pulse is 118/min, and respirations are 20/min. The patient is oriented to person but not place or time. On physical examination, the perineum is erythematous, warm, and tender to palpation; areas of skin sloughing associated with malodorous discharge are present. CT scan of the abdomen and pelvis reveals necrotizing infection of the perineum. Intravenous fluids, insulin, and antibiotics are administered. The surgical team is consulted. The patient repeatedly says, "I just want to go home. Don't cut me." Which of the following is the best next step in management?

A. Continue medical treatment only and determine code status with the patient ✗
B. Discharge the patient after discussing the risks of not receiving treatment ✗
C. Obtain an emergency court order to proceed with surgery ✗
D. Proceed with surgery because it is in the best interest of the patient ✓
E. Reassess whether the patient would like to proceed with surgery when his mental status improves ✗

Key Points:

  • The patient lacks decision-making capacity due to delirium from sepsis (fever, tachycardia, confusion)
  • Fournier gangrene (necrotizing perineal infection) is immediately life-threatening and requires urgent surgical debridement
  • When a patient lacks capacity and faces an emergency, physicians should act in the patient's best interest
  • Waiting for mental status improvement or court orders would cause dangerous delays
  • The principle of "presumed consent" applies - we assume a reasonable person would want life-saving treatment if they could make an informed decision

Question 2

A 27-year-old woman, gravida 1 para 0, at 7 weeks gestation comes to the office for an initial prenatal visit. She feels well and has had no pelvic pain or vaginal bleeding. The patient has no chronic medical conditions and has had no surgeries. Vital signs are normal. Ultrasound shows an intrauterine pregnancy with a fetal heart rate of 158/min. During her visit, she meets with the clinic's financial coordinator who reviews her private insurance benefits. The next week, the patient receives a bill from the clinic. She reviews the charges with her insurance carrier and confirms charges are accurate. The patient does not pay the bill and a week later calls the clinic to tell them she still cannot afford to pay it. The clinic then sends her a letter terminating the physician-patient relationship in 30 days. Which of the following best describes the ethical and legal aspects of this action?

A. The clinic's actions are illegal because the patient has current health insurance coverage. ✗
B. The clinic's actions are illegal because the patient's pregnancy requires ongoing care. ✗
C. The clinic's actions are illegal because patients cannot be turned away only on the basis of finances. ✗
D. The clinic's actions are legally justified because the patient has adequate time to find another physician. ✓
E. The clinic's actions constitute patient abandonment because a therapeutic relationship was already established. ✗

Key Points:

  • Early pregnancy (7 weeks, first trimester) allows adequate time to establish care elsewhere
  • The clinic provided proper 30-day written notice
  • The patient has no immediate medical needs or complications
  • Nonpayment is a legally acceptable reason for termination if proper procedures are followed
  • Legal requirements for termination include: written notice, reasonable transition time, no immediate medical needs
  • While potentially ethically questionable, the clinic's actions satisfy the minimum legal requirements

Question 3

A 16-month-old boy is brought to the pediatrician by his parents for a follow-up visit. The patient was recently diagnosed with a rare genetic disorder that causes severe neurodegeneration in infants. In the past 5 years, a total of 34 cases of this rare genetic disorder had been diagnosed in the US. The exact underlying cause for the disorder is unknown. The parents want to know the prognosis for their son compared to children of the same age who do not have the disorder. Which of the following types of study designs would be the most appropriate for answering the parents' question?

A. Case report ✗
B. Case series ✗
C. Cohort study ✓
D. Cross-sectional study ✗

Key Points:

  • Disease as exposure - The key insight is recognizing that the rare genetic disorder itself is the "exposure" in this scenario. We need to compare children with the disorder (exposed) to those without it (unexposed) to determine prognosis
  • Forward-looking design - Cohort studies follow groups over time to observe outcomes, which is essential for determining prognosis. The parents want to know what will happen to their child in the future
  • Comparison groups - This design allows direct comparison between affected and unaffected children, providing the comparative information the parents are seeking
  • Rare disease application - Even though cohort studies are often challenging for rare diseases, here we have a clearly identified group of affected individuals (34 cases) that can be followed
  • Analytical not descriptive - A cohort study tests hypotheses about associations between risk factors and outcomes, making it suitable for determining if and how the disease impacts development

Question 4

The following vignette applies to next 3 items:
It is estimated that the prevalence of smoking in a population is 50%. A cohort study conducted using a random sample from this population showed that the 5-year risk of ischemic stroke is 1:1000 among smokers and 0.5:1000 among non-smokers.
Item 1 of 3:
What is the relative risk of ischemic stroke among smokers compared to non-smokers?

A. 0.5 ✗
B. 1.0 ✗
C. 2.0 ✓
D. 2.5 ✗
E. 5.0 ✗

Key Points:

  • Relative risk (RR) is calculated by dividing the risk in the exposed group by the risk in the unexposed group:
  • RR = Risk in exposed / Risk in unexposed
  • Risk in exposed (smokers) = 1/1000 = 0.001
  • Risk in unexposed (non-smokers) = 0.5/1000 = 0.0005

  • $$\text{RR} = \frac{\text{Risk in exposed}}{\text{Risk in unexposed}} = \frac{0.001}{0.0005} = 2.0$$

  • Interpretation: Smokers have twice the risk of ischemic stroke compared to non-smokers

Question 5

It is estimated that the prevalence of smoking in a population is 50%. A cohort study conducted using a random sample from this population showed that the 5-year risk of ischemic stroke is 1:1000 among smokers and 0.5:1000 among non-smokers.
Item 2 of 3:
What percentage of ischemic strokes observed in smokers can be attributed to their smoking status?

A. 10% ✗
B. 25% ✗
C. 33% ✗
D. 50% ✓
E. 75% ✗

Key Points:

  • Attributable Risk Percent (ARP) answers the question: "What percentage of the disease in the exposed group is due to the exposure?"

  • $$\text{Formula 1: ARP} = \frac{\text{Risk in exposed} - \text{Risk in unexposed}}{\text{Risk in exposed}} = \frac{0.001 - 0.0005}{0.001} = 0.5 = 50\%$$

  • $$\text{Formula 2: ARP} = \frac{\text{RR} - 1}{\text{RR}} = \frac{2.0 - 1}{2.0} = 0.5 = 50\%$$

  • Interpretation: An ARP of 50% means that half of all strokes among smokers could theoretically be prevented if they didn't smoke

Question 6

It is estimated that the prevalence of smoking in a population is 50%. A cohort study conducted using a random sample from this population showed that the 5-year risk of ischemic stroke is 1:1000 among smokers and 0.5:1000 among non-smokers.
Item 3 of 3:
What percentage of ischemic strokes observed in the population can be attributed to smoking?

A. 10% ✗
B. 25% ✗
C. 33% ✓
D. 50% ✗
E. 75% ✗

Key Points:

  • This question is asking for the Population Attributable Risk Percent (PARP), which differs from the Attributable Risk Percent (ARP) we calculated in the previous question
  • While ARP focuses on risk within the exposed group, PARP measures the proportion of disease in the entire population that can be attributed to the exposure
  • $$\text{Formula 1: PARP} = \frac{\text{Risk in total population - Risk in unexposed}}{\text{Risk in total population}}$$
  • First, calculate the risk in the total population:
  • $$\text{Risk in total pop} = (\text{Risk in smokers} \times \text{Proportion of smokers}) + (\text{Risk in nonsmokers} \times \text{Proportion of nonsmokers})$$
  • $$\text{Risk in total pop} = (0.001 \times 0.5) + (0.0005 \times 0.5) = 0.00075$$
  • Then calculate PARP:

  • $$\text{Formula 1: PARP} = \frac{\text{Risk in total population} - \text{Risk in unexposed}}{\text{Risk in total population}} = \frac{0.00075 - 0.0005}{0.00075} = 0.33 = 33\%$$

  • $$\text{Formula 2: PARP} = \frac{\text{Prevalence} \times (\text{RR} - 1)}{[\text{Prevalence} \times (\text{RR} - 1) + 1]} = \frac{0.5 \times (2.0 - 1)}{[0.5 \times (2.0 - 1) + 1]} = \frac{0.5}{1.5} = 0.33 = 33\%$$

  • This means 33% of all ischemic strokes in the entire population can be attributed to smoking. If smoking were eliminated, we could theoretically prevent 33% of all strokes in the population
  • PARP is always lower than ARP when exposure prevalence is less than 100%
  • PARP takes into account both the strength of association (RR) AND the prevalence of exposure
  • PARP is useful for public health planning and resource allocation, as it helps identify the impact of a risk factor on the entire population

Question 7

A large-scale clinical trial was conducted to assess the effect of carvedilol (a mixed alpha- and beta-blocker) on the clinical course of New York Heart Association class III-IV chronic heart failure. The study reported that serum noradrenaline levels (a marker of the degree of neurohumoral activation) were correlated with serum sodium levels with correlation coefficient r = -0.39 (p = 0.005). Which of the following statements best describes the observed relationship between serum noradrenaline levels and serum sodium levels?

A. Serum noradrenaline levels increase as serum sodium levels decrease ✓
B. Serum noradrenaline levels increase as serum sodium levels increase ✗
C. The measure of association does not reach statistical significance ✗
D. There is a strong correlation between serum noradrenaline and serum sodium levels ✗
E. Variations in serum noradrenaline levels change serum sodium levels ✗

Key Points:

  • Understand correlation coefficients: Correlation coefficients range from -1 to +1
  • The sign (+ or -) indicates the direction of the relationship; Sign → Direction: Negative means inverse relationship; positive means direct relationship
  • The absolute value indicates the strength of the relationship; Magnitude → Strength: Closer to 0 = weaker; closer to 1 (or -1) = stronger
  • p = 0.005 means the finding is statistically significant (p < 0.05). This rules out answer choice C, which incorrectly states the association is not significant
  • Correlation describes a relationship but doesn't imply causation. Answer E incorrectly implies causality ("levels change"). We can only say the variables move in opposite directions
  • Magnitude interpretation: Answer D incorrectly states there is a "strong" correlation. An r value of 0.39 represents a moderate correlation (closer to 0 than to 1)

Thank You!

Questions or Comments?