LAUSR

Introduction Community-integrated care initiatives are increasingly being used for social and health service delivery and show promising outcomes. Nevertheless, it is unclear what structures and underlining causal agents (generative mechanisms) are responsible for explaining how and why they work or not. Methods and analysis Critical realist synthesis, a theory-driven approach to reviewing and synthesising literature based on the critical realist philosophy of science, underpinned the study. Two lenses guided our evidence synthesis, the community health system and the patient-focused perspective of integrated care. The realist synthesis was conducted through the following steps: (1) concept mining and framework formulation, (2) searching for and scrutinising the evidence, (3) extracting and synthesising the evidence (4) developing the narratives from causal explanatory theories, and (5) disseminate, implement and evaluate. Results Three programme theories, each aligning with three groups of stakeholders, were unearthed. At the systems level, three bundles of mechanisms were identified, that is, (1) commitment and motivation, (2) willingness to address integrated health concerns and (3) shared vision and goals. At the provider level, five bundles of mechanisms critical to the successful implementation of integrated care initiatives were abstracted, that is, (1) shared vision and buy-in, (2) shared learning and empowerment, (3) perceived usefulness, (4) trust and perceived support and (5) perceived role recognition and appreciation. At the user level, five bundles of mechanisms were identified, that is, (1) motivation, (2) perceived interpersonal trust, (3) user-empowerment, (4) perceived accessibility to required services and (5) self-efficacy and self-determination. Conclusion We systematically captured mechanism-based explanatory models to inform practice communities on how and why community-integrated models work and under what health systems conditions. PROSPERO registration number CRD42020210442.