A rehabilitation intervention to improve recovery after delirium in older people: mixed methods process evaluation of the RecoverED multi-site feasibility study

A mixed-methods process evaluation was conducted alongside a multi-site feasibility trial of RecoverED, a multicomponent delirium rehabilitation intervention for older people in post-acute settings. A modified Conceptual Model for Implementation Fidelity was used. Findings on implementation and acceptability are presented. Older adults with delirium, their carers, and trained healthcare professionals (HCPs) from six UK NHS hospitals participated. Adherence to content, dose, and coverage, alongside moderating factors such as recruitment, context, and delivery quality, were examined. Findings from in-depth interviews, focus groups, trial documentation, and training logs were triangulated. Nineteen participant-carer pairs were recruited to the study. Post-intervention, five older adults, nine carers, and eight HCPs participated in interviews, while seven HCPs took part in focus groups. Adherence to content was challenging to assess due to the intervention’s personalised nature. Psychosocial support was delivered more frequently than planned. Participant-led goals were highly valued, with strong engagement and perceived benefit. Implementation was largely as intended. Most withdrawals (N = 10) were attributed to complex needs. No participants from minority ethnic backgrounds were recruited. The RecoverED intervention was acceptable, though recruitment and retention challenges necessitate caution when interpreting acceptability and fidelity to dose and coverage. Implementation fidelity was high and well-received.