What is the primary focus of a case-control study?

A case-control study primarily focuses on comparing characteristics between individuals with a particular outcome (cases) and those without it (controls) to identify potential risk factors or associations. In this type of study, researchers do not measure incidence or prevalence directly. Instead, they look back in time to find exposure status, which helps in identifying whether a particular exposure is associated with the outcome of interest.

Incidence refers to the occurrence of new cases in a defined population over a specified time period, while prevalence represents the total number of cases, both new and existing, within a population at a given time. Since case-control studies are retrospective and not designed to establish the incidence or prevalence of the outcome being studied, they do not provide direct measurements of these epidemiological parameters. Instead, the focus is on odds ratios to establish associations rather than rates of occurrence. Thus, the correct response indicates that case-control studies do not primarily aim to measure incidence or prevalence.