Implementation of a complex intervention to improve hospital discharge: process evaluation of a cluster randomised controlled trial

Objectives To study the implementation of a cluster randomised controlled effectiveness-implementation hybrid trial testing effectiveness medication review at hospital discharge combined with communication stimulus between physicians (HPs) and general practitioners (GPs) on rehospitalisation multimorbid older patients. Design Extension Grant’s mixed method process evaluation framework to trials multilevel clustering. Setting General internal medicine wards in Swiss hospitals. Participants Convenience samples 15 chief (of 21 hospitals participating trial), 60 (74) senior HPs, 65 (164) junior HPs 187 (411) GPs. Implementation strategy Two-hour teaching sessions for patient-centred, checklist-guided routine. Process components Data collection recruitment, delivery response from (semistructured interviews), GPs (surveys) patients (via HPs). Quantitative data were summarised using descriptive statistics, interviews analysed thematic analysis. Outcome measures Intervention dose (quantitative), fidelity (qualitative), feasibility acceptability, facilitators barriers, support strategies. Results Recruitment was laborious but successful, recruited. Minimal workload perceived benefit clinic crucial factors participation. high (95% checklist activities carried out), intervention limited (discharge letters) or unknown (medication review). retention challenging, partly due patient characteristics (old, frail) COVID-19 pandemic: Only 612 anticipated 2100 recruited, 31% lost follow-up within first month after discharge. The deemed feasible helpful by relevance topic appreciated both Conclusions results this will interpretation findings may inform researchers policy makers who aim improving Trial registration number ISRCTN18427377 .