Implement social prescribing successfully towards embedding: what works, for whom and in which context? A rapid realist review.

Background: Some clients who access healthcare services experience problems due to the wider determinants of health which cannot be addressed (solely) by the medical sector. Social Prescribing (SP) addresses clients ' wider health needs and is based on linkworkers who support primary care clients in accessing social, community and voluntary care services that support their needs. Previous literature has provided valuable insights about what works (or not) in an early stage of implementing SP. However, there is limited insight into what works for the implementation of SP towards embedding. This study provides guiding principles by which SP can be successfully implemented towards the embedding stage and identifies which contextual factors and mechanisms influence these guiding principles.

Methods: A Rapid Realist Review was conducted to examine what works, for whom, why, and in which contexts. A local Dutch reference panel consisting of health and care organisations helped to inform the research questions. Additionally, a workshop was held with the panel, to discuss what the international insights mean for their local contexts. This input helped to further refine the literature review's findings.

Results: Five guiding principles were identified for successful implementation of SP at the embedding stage: • Create awareness for addressing the wider determinants of health and the role SP services can play; • Ensure health and care professionals build trusting relationships with all involved stakeholders to create a cyclical referral process; • Invest in linkworkers' skills and capacity so that they can act as a bridge between the sectors; • Ensure clients receive appropriate support to improve their self-reliance and increase their community participation; • Invest in the aligning of structures, processes and resources between involved sectors to support the use of SP services.

Conclusion: To embed SP, structural changes on a system level as well as cultural changes are needed. This will require a shift in attitude amongst health and care professionals as well as clients towards the use, role and benefit of SP services in addressing the wider determinants of health. It will also require policymakers and researchers to involve communities and include their perspectives.