Cohort Studies—A Brief Overview

Cohort studies represent one of the most powerful tools in the pharmacoepidemiologist's armamentarium; they overcome the limitations of the other observational designs and allow for investigation of the causal nature of an observed association. Retrospective cohort studies often involve large samples and permit investigators to address questions regarding safety and effectiveness of different medications. In addition, they allow one to use modern methodology to investigate exposure-disease associations using the causal inference framework.