NBME - Behavioral Science: Epidemiology/Biostatistics
Questions with Correct Answers 2025/2026
Collects data from a group of people to assess frequency of disease at a particular point in time.
Asks, "What is happening?" - CORRECT ANSWER -Cross-sectional study (observational)
Measures disease prevalence - can show risk factor association with disease, but does not
establish causality. - CORRECT ANSWER -Cross-sectional study (observational)
Compares a group of people with disease to a group without disease. Asks, "What happened?" -
CORRECT ANSWER -Case-control study
Measures and odds ratio (OR) - "Patients with COPD had a higher odds of a history of smoking
than those without COPD." - CORRECT ANSWER -Case-control study
Compares a group with a given exposure or risk factor to a group without such exposure. Looks
to see if exposure increases risk for disease. - CORRECT ANSWER -Cohort study
Measures relative risk (RR) = 'Smokers had a higher risk of developing COPD than nonsmokers."
- CORRECT ANSWER -Cohort study
Compares the frequency with which both monozygotic twins or both dizygotic twins develop
the same disease. - CORRECT ANSWER -Twin concordance study
Measures heritability and influence of environmental factors (nature vs. nurture). - CORRECT
ANSWER -Twin concordance study
Experimental study involving humans that compares therapeutic benefits of 2 or more
treatments, or of treatment and placebo. - CORRECT ANSWER -Clinical trial
Questions with Correct Answers 2025/2026
Collects data from a group of people to assess frequency of disease at a particular point in time.
Asks, "What is happening?" - CORRECT ANSWER -Cross-sectional study (observational)
Measures disease prevalence - can show risk factor association with disease, but does not
establish causality. - CORRECT ANSWER -Cross-sectional study (observational)
Compares a group of people with disease to a group without disease. Asks, "What happened?" -
CORRECT ANSWER -Case-control study
Measures and odds ratio (OR) - "Patients with COPD had a higher odds of a history of smoking
than those without COPD." - CORRECT ANSWER -Case-control study
Compares a group with a given exposure or risk factor to a group without such exposure. Looks
to see if exposure increases risk for disease. - CORRECT ANSWER -Cohort study
Measures relative risk (RR) = 'Smokers had a higher risk of developing COPD than nonsmokers."
- CORRECT ANSWER -Cohort study
Compares the frequency with which both monozygotic twins or both dizygotic twins develop
the same disease. - CORRECT ANSWER -Twin concordance study
Measures heritability and influence of environmental factors (nature vs. nurture). - CORRECT
ANSWER -Twin concordance study
Experimental study involving humans that compares therapeutic benefits of 2 or more
treatments, or of treatment and placebo. - CORRECT ANSWER -Clinical trial
