Process evaluation protocol of a trial evaluating app-based post knee arthroplasty telerehabilitation strategy in India

Background Physical rehabilitation after knee arthroplasty is essential for improving functional outcomes. However, adherence to rehabilitation is poor. We developed a multicomponent mobile application TeleREhabilitation after knee ArThroplasty (TReAT app) comprising education, exercise videos, an e-diary for self-monitoring progress, two-way communication, and remote therapy planning to facilitate home-based rehabilitation. The TReAT trial is a 1:1 randomized controlled superiority trial to evaluate the clinical and cost-effectiveness of the intervention against usual care, with an embedded process evaluation. This paper reports the protocol for process evaluation. Methods and analysis Consenting individuals undergoing knee arthroplasty at a public and private tertiary care hospital in Delhi, who are able to use a smartphone will be randomized to either app-based or usual home-based rehabilitation and followed up at 3 and 6 months to assess knee-related functional outcomes. A mixed-methods convergent parallel design supported by a logic model will be used for a process evaluation. Data from screening log, backend app analytics, interviews with end users, and researcher notes will contribute to the evaluation based on RE-AIM framework. Researcher notes will be quantified and, consolidated with app analytics to summarise fidelity, and adoption. Thematic analysis of interviews will provide insights into contextual factors influencing intervention adoption during the trial and intention to use the TReAT app beyond the trial period. To explore potential association between use of intervention components and outcomes, correlations between functional outcomes, knowledge score and rehabilitation self-efficacy will be examined. Conclusions The process evaluation will provide insights into the potential uptake and scalability of TReAT intervention. Comparing findings across public and private healthcare settings will enhance understanding of how the intervention functions in different contexts. The findings will inform implementation strategies to improve rehabilitation care using mHealth interventions in India. Trial registration The trial was registered prospectively with the Clinical Trial Registry of India (CTRI/2024/06/068838).