Peer-based health interventions for people with serious mental illness: A systematic literature review

Health interventions delivered by peer specialists or co-facilitated by peer specialists and health professionals can help improve the physical health of people with serious mental illness (SMI). Yet, the quality of the studies examining these health interventions and their impact on health outcomes remains unclear. To address this gap, we conducted a systematic literature review of peer-based health interventions for people with SMI. We rated the methodological quality of studies, summarized intervention strategies and health outcomes, and evaluated the inclusion of racial and ethnic minorities in these studies. We used the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines to conduct our systematic literature review. Electronic bibliographic databases and manual searches were used to locate articles that were published in English in peer-reviewed journals between 1990 and 2015, described peer-based health interventions for people with SMI, and evaluated the impact of the interventions on physical health outcomes. Two independent reviewers used a standardized instrument to rate studies' methodological quality, abstracted study characteristics, and evaluated the effects of the interventions on different health outcomes. Eighteen articles were reviewed. Findings indicated that the strength of the evidence generated from these studies is limited due to several methodological limitations. Mixed and limited intervention effects were reported for most health outcomes. The most promising interventions were self-management and peer-navigator interventions. Efforts to strengthen the evidence of peer-based interventions require a research agenda that focuses on establishing the efficacy and effectiveness of these interventions across different populations and settings.