In case-control studies, which measure is typically used to estimate the association between exposure and outcome?

• A. Relative Risk
• B. Hazard Ratio
• C. Odds Ratio
• D. Prevalence Ratio

Answer: (B)

In case-control studies, the typical measure is the odds of exposure among cases compared with controls. Since participants are selected by outcome status (having or not having the outcome), you can’t directly estimate risk or incidence from the design. The odds ratio captures how much more (or less) likely exposure is among cases than controls, and it serves as an estimator of the relative risk when the disease is rare in the population. Hazard ratios come from time-to-event analyses in cohort studies, not case-control designs. Relative risk requires cohort data to observe incidence, and prevalence ratio comes from cross-sectional data. So the odds ratio is the appropriate and standard measure for case-control studies.