Systematic Literature Review of Peer-Based Health Interventions for People with Serious Mental Illness

Background & Purpose.  People with serious mental illness (SMI; schizophrenia) die at an earlier age compared to the general population, largely due to preventable medical conditions (e.g. cardiovascular disease, diabetes). Health interventions delivered by peer specialists, who are individuals with lived experience of mental illness and trained to support others, are a viable approach to improving the physical health of people with SMI. Peer specialists are a growing segment of the mental healthcare workforce. They bring credibility, trust, and hope to people with SMI and serve as positive role models who can tap into their own experiences to provide clients with instrumental, informational, and emotional support. The aim of this study was to conduct a systematic literature review of the existing peer-based health intervention literature. In this review, we rated the methodological quality of published peer-based health intervention studies for people with SMI, summarized intervention strategies, examined the physical health outcomes of these interventions, and evaluated the inclusion of racial/ethnic minority groups in these studies.

Methods. We used the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines to conduct our systematic literature review. Electronic bibliographic database (e.g., Medline, PsychInfo) and manual searches were used to locate articles written in English and published in peer-reviewed journals from 1990 to the present. Our search strategy included terms for SMI, physical health interventions, and peer specialists. Articles included met the following criteria: (1) described a peer-based health intervention for people with SMI and (2) reported physical health outcomes. Two reviewers working independently rated the methodological quality of each article using the Methodological Quality Rating Scale and abstracted key study characteristics (e.g., study aims, designs, key findings).

Results.  Eleven articles were included. Seven studies were based in the United States and four were conducted in Australia. Based on studies’ methodological quality ratings, three levels of evidence were found: pre-test, post-test single group reports (n = 7); quasi-experimental study (n =1); and randomized controlled trials (n = 3). Study samples ranged from 12 to 183 participants and included people with different mental health conditions (e.g., schizophrenia, schizoaffective disorder). Several health interventions were tested including self-management programs for chronic medical illnesses, smoking cessation interventions, healthy lifestyle interventions, and patient navigation programs. All but one study used manualized interventions. Peer specialist roles included leading individual or group sessions, or co-facilitating the intervention with a health or mental health professional. The majority of studies (64%) reported statistically significant improvements in health outcomes (e.g., self-management behaviors, use of primary care services, smoking cessation, health-related quality of life). Persons from racial/ethnic minority groups were underrepresented in these studies, particularly Hispanics (3%) and other minorities (4%). No study included Asians, Native Americans, and non-English speaking participants.

Implications. The findings from this systematic literature review indicate that peer-based health interventions show promise in improving the physical health of people with SMI, but more rigorous studies that include diverse populations are needed to advance the knowledge base of this emerging literature.  Implications for social work research and practice will be discussed.