A process evaluation of a home-based occupational therapy intervention for Parkinson’s patients and their caregivers performed alongside a randomized controlled trial

OBJECTIVE: To evaluate fidelity, treatment enactment and the experiences of an occupational therapy intervention in Parkinson's disease, to identify factors that affect intervention delivery and benefits. DESIGN: Mixed methods alongside a randomized controlled trial. SUBJECTS: These include 124 home-dwelling Parkinson's disease patients and their primary caregivers (recipients), and 18 occupational therapists. INTERVENTION: Ten-week home-based intervention according to the Dutch guidelines for occupational therapy in Parkinson's disease. MAIN MEASURES: Data were collected on intervention dose, protocol process, content of treatment (fidelity), offered and performed strategies (treatment enactment), and recipients' experiences. Therapists' experiences were collected through case note analyses and focus group interviews. RESULTS: Mean intervention dose was 9.3 (SD 2.3) hours. Mean protocol process adherence was high (93%; SD 9%), however the intervention did not (fully) address the goal for 268 of 617 treatment goals. Frequencies of offered and performed strategies appeared similar, apart from 'using other tools and materials' which showed a drop from 279 advised to 149 used. The recipients were satisfied overall with the intervention (mean score 8 out of 10). The therapists noted positive or negative influencing factors on both process and benefits: the research context, the socio-political healthcare context, the recipients' personal and contextual factors, and the therapists' competence. CONCLUSION: We found some prerequisite factors in equipment provision and available dose important for treatment delivery. Other elicited factors related to, or affected, the required professional competencies and tools to tailor interventions to the complexity of interacting personal and contextual factors of patients and caregivers.