What type of study compares a group of individuals with a disease to individuals without that disease?

A case-control study is specifically designed to compare individuals who have a certain disease (the cases) with individuals who do not have the disease (the controls). This type of study is particularly useful for understanding potential risk factors associated with the disease by looking back retrospectively at the differences between the two groups.

In this design, researchers collect data about past exposures, behaviors, or characteristics that may have contributed to the development of the disease in the case group compared to the control group. The focus on comparing these two distinct groups allows for an efficient examination of associations, especially useful for rare diseases where finding a large number of affected individuals can be challenging.

Cross-sectional studies, on the other hand, assess both exposure and outcome at a single point in time, making it difficult to establish a clear cause-and-effect relationship. Longitudinal studies involve following the same group of individuals over time to observe changes and outcomes, and cohort studies track a group based on their exposure status but do not specifically select groups based on their disease status.