Exploring the Association between Individual-Level Attributes and Fidelity to a Vocational Rehabilitation Intervention within a Randomised Controlled Trial

Understanding what attributes or characteristics of those delivering interventions affect intervention fidelity and patient outcomes is important for contextualising intervention effectiveness. It may also inform implementation of interventions in future research and clinical practice. This study aimed to explore the relationships between attributes of Occupational Therapists (OTs), their faithful delivery of an early stroke specialist vocational rehabilitation intervention (ESSVR), and stroke survivor return-to-work (RTW) outcomes. Thirty-nine OTs were surveyed about their experience and knowledge of stroke and vocational rehabilitation and were trained to deliver ESSVR. ESSVR was delivered across 16 sites in England and Wales between February 2018 and November 2021. OTs received monthly mentoring to support ESSVR delivery. The amount of mentoring each OT received was recorded in OT mentoring records. Fidelity was assessed using an intervention component checklist completed using retrospective case review of one randomly selected participant per OT. Linear and logistic regression analyses explored relationships between OT attributes, fidelity, and stroke survivor RTW outcome. Fidelity scores ranged from 30.8 to 100% (Mean: 78.8%, SD: 19.2%). Only OT engagement in mentoring was significantly associated with fidelity (b = 0.29, 95% CI = 0.05–0.53, p < 0.05). Increased fidelity (OR = 1.06, 95% CI = 1.01–1.1, p = 0.01) and increasing years of stroke rehabilitation experience (OR = 1.17, 95% CI = 1.02–1.35) was significantly associated with positive stroke survivor RTW outcomes. Findings of this study suggest that mentoring OTs may increase fidelity of delivery of ESSVR, which may also be associated with positive stroke survivor return-to-work outcomes. The results also suggest that OTs with more experience of stroke rehabilitation may be able to support stroke survivors to RTW more effectively. Upskilling OTs to deliver complex interventions, such as ESSVR, in clinical trials may require mentoring support in addition to training to ensure fidelity.