Understanding a Complex Intervention to Reduce Unplanned Hospitalizations From Nursing Homes: Process Evaluation of INTERCARE.

Background and Aims: The INTERCARE study aimed to reduce unplanned hospitalizations in Swiss nursing homes (NH) by implementing a complex nurse-led model featuring nurses with in-depth geriatric training (INTERCARE nurse). To optimize the intervention for scale-up, this process evaluation aims to describe the intervention elements' use in practice, to explore related barriers and facilitators, and to explore the mechanisms of change. Methods: The process evaluation was conducted alongside the INTERCARE study guided by the Medical Research Council's framework. We combined qualitative data from participating NHs via individual interviews and focus groups with care workers, INTERCARE nurses and physicians. Additionally, structured notes from meetings with NH leadership teams were included. For each intervention element, data were compiled into a spreadsheet, followed by inductive coding. Changes reported by NHs related to the intervention were summarized and consolidated in a conceptual model. Results: Our analysis revealed two groups of intervention mechanisms: (1) those changing care workers' reasoning, for example, following a more structured approach to perform tasks (e.g., with the help of evidence-based instruments) and (2) those enabling existing resources, for example, availability of a responsible contact person (i.e., the INTERCARE nurse). We further identified behavior changes in care workers, including faster reaction to changes in resident situations, more comprehensive assessment of resident situations and improved communication, which contributed to the reduction of hospitalizations. Conclusions: Understanding how interventions work in practice is crucial to inform potential adaptations to complex interventions. We found interprofessional collaboration supported by evidence-based instruments and the INTERCARE nurse to be key elements to drive the reduction of unplanned hospitalization, together with the use of ACP. The findings can help not only to optimize the intervention elements for scale-up, but also hold implications for refining alternative care models, ultimately reducing unplanned hospitalizations in NH residents.