We sincerely thank Dr Sophie Hill, Coordinating Editor of the Review Group, for her advice and support as contact editor of this review.

Many thanks to Ms Judy Stoelwinder and Ms Shirley Ward (former and current Trials Search Coordinators (respectively), Cochrane Consumers and Communication Review Group) for the elaboration of the search strategy and for providing extensive assistance with retrieval of studies, and to Ms Kelly Allen and Associate Professor Damien Jolley (Statistics Assistant and Statistics Editor, Consumers and Communication Review Group) for comprehensive checking of the data and analysis.

We thank the following people for their comments on the protocol from a consumer's perspective: Grindl Dockery, Community Research and Training Consultant (the Gender and Health group, Liverpool School of Tropical Medicine, Liverpool, UK); Kristin McCarthy (Director, Developing Patient Partnerships ‐formerly Doctor Patient Partnership, London, UK); Margaret Yarwood (Link Forum Support Network Coordinator), Renee Brenner (Aintree Hospital Trust and Patient Forum). We thank Dr. María Paz Loscertales who commented on the protocol and Dr. Aika Omari and Vittoria Lutje who provided technical guidance in the initial stages. Thanks also to Xavier Carbonell i Santías who assisted with an article in German and Kwang Shik Choi, in Korean.

Feedback on the protocol and review was received from three external referees (including one consumer) and five members of the editorial team of the Consumers and Communication Review Group.