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Composite outcomes in clinical trials: uses and problems

António Vaz Carneiro1

  • 1Centro de Estudos de Medicina Baseada na Evidência, Faculdade de Medicina de Lisboa, Lisboa.

Revista Portuguesa De Cardiologia : Orgao Oficial Da Sociedade Portuguesa De Cardiologia = Portuguese Journal of Cardiology : an Official Journal of the Portuguese Society of Cardiology
|January 8, 2004
PubMed

Insights

Randomized clinical trials (RCTs) establish causation for therapeutic efficacy. This article discusses the uses and potential problems of composite outcomes in RCTs, emphasizing rigorous selection and definition.

Area of Science:

  • Clinical Trials Methodology
  • Medical Statistics
  • Evidence-Based Medicine

Background:

  • Randomized clinical trials (RCTs) are essential for establishing therapeutic causation and drug licensing.
  • Selection of primary and secondary outcome measures is a critical step in RCT design.
  • Composite outcomes are increasingly used but present potential challenges.

Purpose of the Study:

  • To discuss the uses of composite outcomes in randomized clinical trials.
  • To highlight potential problems and considerations associated with composite outcomes in RCTs.

Main Methods:

  • Review of the literature on composite outcomes in randomized clinical trials.
  • Discussion of best practices for defining and using composite outcomes.

Main Results:

  • Composite outcomes are common in RCTs, serving as primary or secondary endpoints.
  • Potential issues include the use of non-validated surrogate endpoints, excessive numbers, and careful construction when including all-cause mortality.

Conclusions:

  • The choice and definition of composite outcomes in RCTs require careful consideration to ensure clinical relevance and prognostic significance.
  • Rigorous methodology is essential for valid interpretation of RCT results using composite outcomes.

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