What characterizes a case-control study?

A case-control study is characterized by its focus on comparing individuals who have a certain condition or disease (the cases) with those who do not have the disease (the controls). This design allows researchers to identify potential risk factors or associations that may contribute to the disease's development. By examining past exposures or characteristics of participants in both groups, researchers can infer relationships that may warrant further investigation.

This approach is particularly valuable in studying rare diseases, where gathering a large cohort of affected individuals for an observational study can be challenging. Instead, researchers can more efficiently gather data by starting with the outcome (the presence or absence of the disease) and looking backward to assess possible exposures or risk factors.

Other research designs, such as cohort studies or randomized controlled trials, do not share this specific comparative focus. Cohort studies generally observe groups over time to see how exposure impacts outcomes, while randomized controlled trials involve assigning subjects to specific treatments to compare effects directly, neither of which aligns with the fundamental structure of a case-control study.