What is a case-control study?

A case-control study is a type of observational research design that compares two groups of subjects: those who have a specific condition or outcome (the cases) and those who do not have the condition (the controls). The purpose of this study design is to investigate potential risk factors or exposures that may be associated with the condition under study. By examining the differences in exposure histories between the two groups, researchers can identify associations that may suggest a causal relationship.

This design is particularly useful for studying rare diseases or outcomes, as it allows researchers to efficiently gather information about individuals who already have the condition without needing to follow them over time, as is the case with cohort studies. The focus on past exposure and retrospective data collection helps illuminate possible pathways that lead to the condition.

The other options do not accurately describe a case-control study. For instance, a study that looks only at cases without controls would not allow for any comparative analysis, nor would it help to identify potential causative factors. Similarly, stating it lacks comparison conflicts with the very essence of what a case-control study aims to do—make a comparison between individuals with and without the condition. Lastly, focusing solely on prevention measures is not characteristic of case-control studies, as these studies primarily seek to identify and analyze