Background: Core outcome sets (COS) represent agreed-upon minimum outcomes that should be reported in all studies in a given topic area. Among the first 100 Cochrane systematic reviews (SRs) published in 2019, 7 (7%) cited a COS in relation to choosing outcomes. A relevant COS existed but was not mentioned (or cited) for 27 of the remaining 93 SRs (29%). Among Cochrane Review Group editors surveyed in 2019, 86% felt that COS should definitely/possibly be used in Cochrane SRs. The Cochrane Handbook now recommends including outcomes from relevant COS.
Objectives: (1) Examine whether authors are currently considering COS to inform outcome choice for Cochrane SRs. (2) Understand author barriers and facilitators of using COS in Cochrane SRs.
Methods: We examined the extent to which all Cochrane SRs published in the last 3 months of 2022 and all Cochrane protocols published in 2022: (a) cited a COS, (b) searched for COS, and (c) reported outcome inconsistency among included studies and/or noted the need for COS. We will conduct an online anonymous survey of authors of these SRs to identify barriers and facilitators of using COS to inform outcome choice.
Results: Among the 88 eligible SRs, 13 SRs (15%) cited a COS and 1 additional SR (1%) mentioned searching for COS. Among the 74 SRs that did not cite or search for COS, 17 SRs (23%) reported outcome inconsistency among included studies and/or the need for standardized outcomes/COS. Among the 231 eligible protocols, 24 (10%) cited a COS and an additional 14 protocols (6%) searched for COS. Twenty-three of the 37 protocols that searched for COS (62%) found and used one. At the Colloquium, we will describe how the SRs and protocols that cited COS used those outcomes. We will also present insights from the author survey.
Conclusions: Although more than twice the Cochrane SRs (16%) and protocols (16%) in 2022 are considering COS than Cochrane SRs in 2019 (7%), the persistent problem of outcome inconsistency merits greater use of COS in Cochrane SRs. Patient Involvement: Although no patients were involved in this abstract, COS are developed with various stakeholders, including patients.