Video - Case-control study

A case-control study is an observational method used to compare a group of individuals with a particular condition (the cases) to another, a similar group of people without that condition (the controls). The investigation begins after researchers have identified a group of people with the condition they wish to study. A second, comparable group who does not have the condition is then identified from medical records or other sources. Investigators then look back through both groups' records to identify possible causes or risk factors for the condition. Case-control studies can be conducted relatively quickly and cheaply since researchers don't have to follow participants over time as they would in a cohort study. Another advantage is that case-control studies can be used to study rare conditions that would be challenging in a cohort study.