Interpreting composite outcomes in trials Difficulty lies in poor reporting, not the measure itself

摘要

The potential problems with the use of composite outcomes in clinical trials are well known. The linked systematic review by Cordoba and colleagues indicates that many of these challenges are long lasting. This review of 40 trials published in 2008 that reported a composite primary outcome found little justification for the choice of outcome, imbalance in the importance of different components in 70% of trials, and problems in the definition and reporting of composite outcomes in 40% of trials. Before we abandon composite outcomes because of the authors' assertion that their use leads to much confusion and bias, we should consider carefully the opportunity cost and tackle some commonly held misconceptions on composites.