Related Experiment Video
Updated: Sep 18, 2026

Ex Vivo Treatment Response of Primary Tumors and/or Associated Metastases for Preclinical and Clinical Development of Therapeutics
Published on: October 2, 2014
Use of core outcome sets was low in clinical trials published in major medical journals
Karen Matvienko-Sikar1, Kerry Avery2, Jane M Blazeby2
1School of Public Health, University College Cork, Ireland.
Objectives:
To examine current practices in late-phase trials published in major medical journals and examine trialists' views about core outcome set (COS) use.
Study Design And Setting:
A sequential multi-methods study was conducted. We examined late-phase trials published between October 2019 and March 2020 in JAMA, NEJM, The Lancet, BMJ, and Annals of Internal Medicine. The COMET database was searched for COS potentially relevant to trials not reporting using a COS; overlap of trial and COS outcomes was examined. An online survey examined awareness of, and decisions to search for and use a COS.
Results:
Ninety-five trials were examined; 93 (98%) did not report using a COS. Relevant COS were identified for 31 trials (33%). Core outcomes were measured in 9 (23%) studies; all trials measured at least one core outcome. Thirty-one trialists (33%) completed our survey. The most common barrier to COS use was trialist's own outcome preferences and choice (68%). The most common perceived facilitator was awareness and knowledge about COS (90%).
Conclusion:
COS use in this cohort of trials was low, even when relevant COS were available. Increased use of COS in clinical trials can improve evaluation of intervention effects and evidence synthesis and reduce research waste.
Related Concept Videos
Clinical Trials
There are four phases in a clinical trial. A phase one...
Standards of Care I
Standards of Care II
Clinical Trials: Overview
Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and case-control studies.
Bias in Epidemiological Studies

