Implementation context, mechanisms and outcomes of a transitional care intervention to prevent delirium: a mixed-methods process evaluation from the TRADE study.

Background: While predisposing factors for delirium, like old age or surgery, are well documented, less attention has been paid to environmental factors, including hospital transfer processes and caregiver involvement in transitional care of older patients. To address this gap, we developed a pathway to optimize hospital transfer processes and actively involve caregivers in preventing delirium. This complex intervention was tested in a pilot study using a stepped-wedge design across four hospitals, accompanied by a process evaluation to explore the implementation context, mechanisms and outcomes of this intervention.

Methods: A parallel convergent mixed-methods process evaluation was used. Qualitative data and quantitative data were analyzed separately and integrated using a weaving approach. Analyses were guided by Normalization Process Theory, supplemented by implementation impact ratings based on the Consolidated Framework for Implementation Research rating tool.

Results: Data included 72 interviews, 2 focus groups, 82 document analyses, 14 status analyses, 424 TRADE questionnaires, 58 Normalization MeAsure Development questionnaires, and website traffic metrics. COVID-19-related constraints resulted in partial implementation of the intervention, with challenges such as limited training opportunities and restricted caregiver involvement. Healthcare professionals reported greater delirium awareness, and educational materials received positive feedback.

Conclusion: The study underscores the critical role of discharge information, post-discharge support, and education for caregiver and healthcare professionals in preventing delirium. It also provides evidence of how the COVID-19 pandemic impacted standard care and the implementation of clinical interventions, emphasizing the need for adaptable processes and institutional support. Furthermore, it offers theoretical and methodological insights into conducting mixed-methods process evaluations in complex intervention research.

Trial registration: German Clinical Trials Register (ID: DRKS00017828, retrospectively registered on 17.09.2019, https://drks.de/search/en/trial/DRKS00017828 ).