What defines a case-control study?

A case-control study is uniquely defined by its approach to comparing individuals based on the presence or absence of a specific condition. In this study design, researchers select a group of individuals who have the condition (the cases) and a group who do not have the condition (the controls). This allows for the examination of prior exposures, risk factors, or characteristics that may contribute to the condition in question.

By focusing on these two distinct groups, researchers can identify potential associations and generate hypotheses regarding causation. This retrospective approach is particularly useful in studying rare diseases or conditions where the outcome has already occurred, as it allows researchers to gather data efficiently without needing to follow a larger population over time. This is fundamentally different from prospective or randomized studies, which involve extensive monitoring and may focus on a broader population rather than specific cases.