Survey of new 2007 and 2011 Cochrane reviews found 37% of prespecified outcomes not reported

J Clin Epidemiol. 2015 Mar;68(3):237-45. doi: 10.1016/j.jclinepi.2014.09.022. Epub 2014 Nov 18.


Objectives: To survey the outcomes used in Cochrane Reviews, as part of our work within the Core Outcome Measures in Effectiveness Trials Initiative.

Study design and setting: A descriptive survey of Cochrane Reviews, divided by Cochrane Review Group (CRG), published in full for the first time in 2007 and 2011. Outcomes specified in the methods section of each review and outcomes reported in the results section of each review were of interest, in this exploration of the common use of outcomes and core outcome sets (COS).

Results: Seven hundred eighty-eight reviews, specifying 6,127 outcomes, were included. When we excluded specified outcomes from the 86 reviews that did not include any studies, we found that 1,996 (37%) specified outcomes were not reported. Of the 361 new reviews with studies from 2011, 113 (31%) had a "summary of findings" table (SoF). Fifteen broad outcome categories were identified and used to manage the outcome data. We found consistency in the use of these categories across CRGs but inconsistency in outcomes within these categories.

Conclusion: COS have been used rarely in Cochrane Reviews, but the introduction of SoF makes the development and application of COS timelier than ever.

Keywords: COMET; COS; Cochrane collaboration; Core outcome set; Outcome measurement; Systematic reviews.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Clinical Trials as Topic*
  • Health Surveys*
  • Humans
  • Outcome Assessment, Health Care*
  • Publishing / standards*
  • Review Literature as Topic*
  • Selection Bias*