Consumer engagement in health care policy, research and services: A systematic review and meta-analysis of methods and effects.

To assess the effects of consumer engagement in health care policy, research and services. We updated a review published in 2006 and 2009 and revised the previous search strategies for key databases (The Cochrane Central Register of Controlled Trials; MEDLINE; EMBASE; PsycINFO; CINAHL; Web of Science) up to February 2020. Selection criteria included randomised controlled trials assessing consumer engagement in developing health care policy, research, or health services.