AMC MCQ Population Health and Epidemiology 2

Question 1

A case-control study reports an odds ratio of 3.2 for smoking and a rare disease. What does this odds ratio best approximate?

Accepted Answer

The relative risk of the disease

Answer

The absolute risk reduction

Answer

The number needed to treat

Answer

The attributable fraction in the population

Question 2

A new screening test has high sensitivity but low specificity. What is the most likely consequence in a low-prevalence population?

Accepted Answer

Many false positives

Answer

Many false negatives

Answer

High positive predictive value

Answer

Low test recall

Question 3

Which measure quantifies the proportion of disease in exposed individuals attributable to the exposure?

Accepted Answer

Attributable risk (risk difference)

Answer

Prevalence ratio

Answer

Incidence density

Answer

Standardised mortality ratio

Question 4

In a randomised controlled trial, allocation concealment primarily protects against which bias?

Accepted Answer

Selection bias

Answer

Recall bias

Answer

Lead-time bias

Answer

Detection bias from outcome assessors

Question 5

A study finds an association between coffee drinking and lung cancer, but smoking is more common among coffee drinkers. Smoking is best described as a:

Accepted Answer

Confounder

Answer

Effect modifier

Answer

Collider

Answer

Mediator

Question 6

The basic reproduction number (R0) of a measles outbreak is 15. Approximately what herd immunity threshold is required to halt transmission?

Accepted Answer

About 93%

Answer

About 50%

Answer

About 15%

Answer

About 75%

Question 7

Which study design is most appropriate to estimate the prevalence of obesity in a community at a single point in time?

Accepted Answer

Cross-sectional survey

Answer

Prospective cohort study

Answer

Case-control study

Answer

Randomised controlled trial