Why do we need cohort studies?

Cohort studies play an important role in medical research but it is important to understand their limitations. Some large ongoing cohort studies continue to provide critical insights into the causes of chronic disease. Confounding is a major challenge but can be dealt with during both the design and analysis phases of a cohort study. Planning for inclusion of potential confounders in the analysis should be part of the study protocol. The STROBE guidelines have improved the performance and reporting of cohort studies.