Physical activity services for inpatients in secure mental health settings: what works, for whom, under what circumstances and why? A realist synthesis

Physical activity (PA) has multiple benefits for people with severe mental illness (SMI). However, more research is needed to determine optimal delivery methods in secure inpatient settings. Realist synthesis, a theory-driven evidence review, has key methodological advantages for evaluating complex interventions and is well-suited to address the research-practice gap concerning the delivery of PA inpatient programmes. This realist synthesis explored ‘what works, for whom, under what circumstances, and why’ in enhancing PA engagement among inpatients with SMI in secure psychiatric settings. We conducted a two-phase realist synthesis. We searched seven bibliographic databases and supplemented this with hand searches to identify grey and additional literature sources. No restrictions were applied to the types of articles included. A total of 65 sources of evidence contributed to the synthesis. The evidence was extracted, assessed and synthesised. Two programme theories, underpinned by six context-mechanism-outcome configurations, were developed. Programme theory one emphasises the crucial role of PA providers in implementing PA programmes. Deliverers must display relational and delivery competencies to earn the trust and confidence of service users (SUs). Building and nurturing these relationships is especially important for SUs who have had previous coercive experiences with mental health services. Programme theory two underscores the importance of providing deliberate (e.g. gym sessions) and incidental PA opportunities (e.g. fun and engaging ward activities) to ensure that all SUs can access daily activities, even if they do not wish to be formally active. Engagement in these opportunities should be voluntary, not mandatory. For SUs with negative past PA experiences, activities should be perceived as enjoyable, meaningful, and achievable to encourage their future participation. This synthesis produced evidence-informed programme theories and underlying context-mechanism-outcome configurations that can inform the design, development, and delivery of PA programmes in inpatient healthcare settings. • Physical activity has multiple benefits for people with severe mental illness (SMI). • Realist methodology has key advantages for evaluating complex programmes. • Realist methods identify causal mechanisms and how they work under what circumstances. • High-quality and trusting relationships are essential for delivery. • Causal mechanisms include agency, trust, achievement, affect, and relatedness.