What is the primary focus of epidemiology in relation to exposures and health outcomes?

• A. To determine the efficacy of a vaccine in a clinical trial
• B. To map the distribution of disease in a population
• C. To study the economic impact of disease burden
• D. To determine the association between exposure, risk factors and health outcomes

Answer: (D)

Epidemiology aims to understand how exposure to risk factors relates to health outcomes in populations. It focuses on quantifying the association between a given exposure and a disease or health outcome, estimating how much exposure changes risk (often using measures like risk or odds ratios), and evaluating how factors like timing, dose, confounding, and bias influence that relationship. This approach turns observations about who gets sick into an understanding of which exposures are linked to disease and how strongly.

That’s why the best choice describes determining the association between exposure, risk factors, and health outcomes. Other options reflect different kinds of work—clinical trials assess vaccine efficacy in controlled settings, mapping disease distribution describes descriptive epidemiology, and studying economic impact falls under health economics rather than exposure-outcome relationships.