The Thames Valley Violence Reduction Unit’s Hospital Navigator Scheme (HNS) supports young people presenting to emergency departments (EDs) at moments of vulnerability. Delivered by volunteer Navigator mentors in partnership with community organisations, the HNS aims to disrupt cycles of vulnerability and violence through relational, needs-led support from the ED into the community. A realist evaluation examined how, for whom, and under what circumstances the HNS achieves its outcomes by developing and refining a middle-range programme theory using context–mechanism–outcome (CMO) configurations. An initial programme theory was iteratively tested and refined through three analytic phases: thematic analysis of 56 case descriptions; quantitative analysis of anonymised audit data from 592 consenting participants (March 2021–December 2022); and semi-structured interviews with 27 stakeholders, which supported explanatory refinement of CMOs to inform a revised, evidence-based programme theory. Four refined CMOs illustrate how the HNS achieves its outcomes: positive initial interactions with Navigator mentors in the ED foster feelings of being understood and perceived value in the scheme, encouraging engagement. Sustained, trusting relationships and flexible, person-centred support build personal agency, enabling ongoing engagement with community services and interrupting cycles of vulnerability or involvement in crime. The HNS demonstrates that early, relational, and context-sensitive intervention in emergency EDs and social development. As the first realist evaluation of an ED-based violence reduction scheme, the study offers novel insights into impact mechanisms and contexts, providing transferable learning for designing, delivering, and evaluating flexible, collaborative hospital-based early intervention models. ● Emergency Departments offer “reachable moments” for early intervention and engagement. ● HNS used trained volunteers with lived experience to support youth. ● Positive outcomes depend on trust, service access, and sustained community links. ● Early, context-sensitive Emergency Department interventions can disrupt cycles of vulnerability and violence.
Bekaert et al. (Wed,) studied this question.