Abstract / Summary
Abstract Background Health systems globally are under increasing strain from ageing populations, multimorbidity, and limited hospital capacity. Virtual wards and hospital-at-home models have emerged as alternatives to deliver hospital-level care at home. However, evidence remains fragmented, particularly regarding mechanisms of effectiveness, sustainability, and equity. Methods A rapid realist review was conducted to examine how, why, and under what circumstances virtual wards are implemented successfully, with particular attention to adult and paediatric populations with unpredictable health deterioration and complex care needs. Evidence was sourced from ten academic databases and grey literature (from 2000 to 2025). Thirty-nine studies from nine countries were included. Data were extracted and synthesised using a realist logic of analysis to develop and refine context–mechanism–outcome configurations and programme theory. Stakeholder engagement informed interpretation of findings and refinement of emerging explanations. Results Common resources underpinning successful virtual wards included remote monitoring, multidisciplinary team support, coordinated follow-up, and structured task-sharing arrangements. These resources generated mechanisms such as reassurance, trust, confidence, perceived safety, and shared ownership of care among patients, caregivers, and professionals. Outcomes were clustered around reduced hospital use, safe care at home, positive patient experience, mixed staff experience, and variable but sometimes favourable economic outcomes. Condition-specific evidence highlighted promising results in heart failure, chronic respiratory disease, and paediatric care. Implementation challenges included digital inequities, workforce strain, and unclear governance. Comparative international evidence demonstrated heterogeneity: while some randomised controlled trials showed no effect, others demonstrated reductions in readmissions among high-risk groups. Hospital-at-home models generally had a stronger evidence base than predominantly technology-enabled virtual ward mode. Key contextual enablers included strong leadership, policy support, workforce capacity, and interoperable digital infrastructure. Conclusion Virtual wards can provide safe and viable alternatives to hospital admission when implemented within supportive contexts and supported by robust multidisciplinary teams, digital inclusion strategies, and clear escalation pathways. However, sustainability and equity depend on workforce capacity, digital inclusion, effective governance, and investment in supporting infrastructure. Future research should prioritise condition-specific pragmatic trials, common outcome sets including caregiver impacts, and full economic evaluations that capture societal costs. This realist-informed programme theory provides an explanatory framework for understanding how virtual wards generate outcomes in different contexts and can guide policy and practice as healthcare systems seek sustainable alternatives to hospital-based care.