Risk tolerance and risk perception as determinants of successful and sustainable hospital admission avoidance interventions: a realist review

BackgroundHealth systems under pressure from rising demand for elective and emergency care are prioritising the reduction of avoidable hospital admissions and the expansion of urgent community care. Yet, inconsistent service provision and fragmented, short-term initiatives have resulted in variable patient experiences, inequities, and inefficient use of resources. The mechanisms driving the success or failure of hospital admission avoidance interventions (HAAIs) remain unclear. This study aimed to develop initial programme theories to understand what makes HAAIs effective, for whom, and in what contexts. MethodsA realist review was undertaken to generate explanatory insights into how complex interventions function in practice. Peer-reviewed and grey literature were eligible for inclusion, with a focus on recent publications. A reverse chronological quota sampling approach was used for screening, supplemented by citation tracking and stakeholder recommendations. Empirical evidence, middle-range theories, and public and professional stakeholder input were synthesised to iteratively develop and refine initial programme theories. ResultsFrom 3,395 records, 68 studies were included in the synthesis. Risk emerged as a central concept shaping how HAAIs are experienced by patients, carers, and healthcare professionals.. Three initial programme theories were developed, each exploring how risk can be managed and navigated in HAAIs: (1) promoting patient and carer acceptance of alternatives to hospital admission (2) nnavigating clinical complexity and uncertainty, and (3) clarifying clinical and organisational roles and responsibilities. Contextual factors, including individual attitudes, interpersonal trust, and organisational risk appetite, were found to influence how these mechanisms operate. ConclusionHAAIs may be most effective when tailored to local contexts, balancing hierarchical and relational mechanisms to manage and navigate risk for patients, carers and healthcare professionals.