Individual and Composite Study Endpoints: Separating the Wheat from the Chaff

We provide an overview of the individual and combined clinical endpoints and patient-reported outcomes typically used in clinical trials and prospective epidemiological investigations. We discuss the strengths and limitations associated with the utilization of aggregated study endpoints and surrogate measures of important clinical endpoints and patient-centered outcomes. We hope that the points raised in this overview will lead to the collection of clinically rich, relevant, measurable, and cost-efficient study outcomes.