Identifying evidence of effectiveness in the co-creation of research: a systematic review and meta-analysis of the international healthcare literature.

Background To investigate and address the evidence gap on the effectiveness of co-creation/production in international health research. Methods An initial systematic search of previous reviews published by 22 July 2017 in Medline, Embase, PsycINFO, Scopus and Web of Science. We extracted reported aims, elements and outcomes of co-creation/production from 50 reviews; however, reviews rarely tested effectiveness against intended outcomes. We therefore checked the reference lists in 13 included systematic reviews that cited quantitative studies involving the public/patients in the design and/or implementation of research projects to conduct meta-analyses on their effectiveness using standardized mean difference (SMD). Results Twenty-six primary studies were included, showing moderate positive effects for community functions (SMD = 0.56, 95%CI = 0.29–0.84, n  = 11) and small positive effects for physical health (SMD = 0.25, 95%CI = 0.07–0.42, n  = 9), health-promoting behaviour (SMD = 0.14, 95%CI = 0.03–0.26, n  = 11), self-efficacy (SMD = 0.34, 95%CI = 0.01–0.67, n  = 3) and health service access/receipt (SMD = 0.36, 95%CI = 0.21–0.52, n  = 12). Non-academic stakeholders that co-created more than one research stage showed significantly favourable mental health outcomes. However, co-creation was rarely extended to later stages (evaluation/dissemination), with few studies specifically with ethnic minority groups. Conclusions The co-creation of research may improve several health-related outcomes and public health more broadly, but research is lacking on its longer term effects. [ABSTRACT FROM AUTHOR]