COMET: Core outcome measures in effectiveness trials

Williamson PR, Altman DG, Bagley H, et al. - Williamson PR, Altman DG, Bagley H, et al. The COMET Handbook: version 1.0. Trials. 2017;18(Suppl 3):280. doi:10.1186/s13063-017-1978-4 - regular updates
  • Research question
  • Develop a protocol
  • Outcome selection and measurement
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doi:10.1186/s13063-017-1978-4

The COMET (Core Outcome Measures in Effectiveness Trials) Initiative can significantly improve clinical trial protocol development by helping investigators select standardised, relevant, and stakeholder-endorsed outcomes. Its primary goal is to promote the use of Core Outcome Sets (COS)—agreed minimum sets of outcomes that should be measured and reported in all clinical trials for a specific health condition. The COMET database focuses on core outcome sets (COS), agreed minimum sets of outcomes for a given condition that should be measured and reported in all clinical trials. COMET is an online database of planned, ongoing and completed COS related studies, covering many disease areas and populations.

When developing a clinical trial protocol, investigators can use the COMET Initiative to:

  • Search for an existing Core Outcome Set relevant to the disease or intervention
  • Justify the selection of primary and secondary outcomes based on stakeholder consensu
  • Ensure that outcomes are clinically meaningful and comparable with those used in other trials
  • Enhance the quality, transparency, and reproducibility of the study.

Overall, incorporating COMET recommendations into protocol development helps investigators design trials that are more patient-centered, scientifically rigorous, and better positioned to contribute to the broader evidence base through consistent outcome measurement.

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