Understanding the Use of Composite Endpoints in Clinical Trials

West J Emerg Med. 2018 Jul;19(4):631-634. doi: 10.5811/westjem.2018.4.38383. Epub 2018 Jun 4.


Clinicians, institutions, healthcare networks, and policymakers use outcomes reported in clinical trials as the basis for medical decision-making when managing individual patients or populations. Therefore, the choice of a valid primary endpoint is crucial for randomized controlled trials (RCT) to demonstrate efficacy of new therapies. Recent improvements in treatment, however, have led to a decline in the morbidity and mortality of several common diseases, resulting in a reduction in relevant outcomes that can be used as clinical trial endpoints. Composite endpoints have been used as a solution to maintain the feasibility of RCTs, particularly when facing low event rates, high cost, and long follow-up. However, the benefits of using composite endpoints must be weighed against the risks of misinterpretation by clinicians and policymakers, as incorrect interpretation may have a detrimental effect on patients and populations. This paper defines a composite endpoint, discusses the rationale for its use, and provides a practical approach to interpreting results to aid in medical decision-making.

Publication types

  • Review

MeSH terms

  • Decision Making
  • Drug Therapy*
  • Endpoint Determination*
  • Humans
  • Randomized Controlled Trials as Topic*
  • Risk Factors