LAUSR

Purpose The evidence base for peer support work in mental health is established, yet implementation remains a challenge. The aim of this systematic review was to identify influences which facilitate or are barriers to implementation of mental health peer support work. Methods Data sources comprised online databases ( n  = 11), journal table of contents ( n  = 2), conference proceedings ( n  = 18), peer support websites ( n  = 2), expert consultation ( n  = 38) and forward and backward citation tracking. Publications were included if they reported on implementation facilitators or barriers for formal face-to-face peer support work with adults with a mental health problem, and were available in English, French, German, Hebrew, Luganda, Spanish or Swahili. Data were analysed using narrative synthesis. A six-site international survey [Germany (2 sites), India, Israel, Tanzania, Uganda] using a measure based on the strongest influences was conducted. The review protocol was pre-registered (Prospero: CRD42018094838). Results The search strategy identified 5813 publications, of which 53 were included. Fourteen implementation influences were identified, notably organisational culture (reported by 53% of papers), training (42%) and role definition (40%). Ratings on a measure using these influences demonstrated preliminary evidence for the convergent and discriminant validity of the identified influences. Conclusion The identified influences provide a guide to implementation of peer support. For services developing a peer support service, organisational culture including role support (training, role clarity, resourcing and access to a peer network) and staff attitudes need to be considered. The identified influences provide a theory base to prepare research sites for implementing peer support worker interventions.