Engagement and fidelity of a cardiovascular disease prevention-focused digital health intervention in cardiology outpatient waiting rooms: a mixed-methods study

INTRODUCTION: We delivered a video-based, cardiovascular disease prevention focused intervention in cardiology waiting rooms that increased motivation to improve cardiovascular risk behaviours and satisfaction with clinic services. To better understand the potential generalisability and scalability of such waiting room interventions, this study evaluated the fidelity of intervention delivery and barriers and enablers to implementation. METHODS: Mixed-methods process evaluation conducted among intervention participants in a randomised clinical trial. Data sources included (1) Participant screening logs, (2) Intervention delivery platform data and (3) Semi structured interviews performed with participants. Qualitative data were described using inductive thematic analysis. RESULTS: The tablet-based intervention was delivered to 220 patients (112 (50.9%) male, mean age 54.2 (SD 15.4) years). Of 765 videos opened, 636 (83.1%) were watched to completion. Most videos opened were rated (738/765, 96.5%) and video ratings were predominantly positive (661/738, (89.6%) satisfied or highly satisfied). Younger and more educated participants were more likely to rate videos highly (relative risk (RR) 1.73 (95% CI 1.28 to 2.32) and RR 1.26 (95% CI 1.07 to 1.49)) but less likely to watch videos to completion (younger: RR 0.27 (95% CI 0.17 to 0.43), more educated: RR 0.90 (95% CI 0.85 to 0.96)). Of 39 invited, 21 (53.8%) participated in semistructured interviews. Thematic analysis of responses suggested reported behaviour change post intervention may be due to increased awareness of cardiovascular risk, reduced anxiety and intrinsic motivation from delivery within a cardiology waiting room. Lack of reinforcement and limited personalisation were barriers. CONCLUSION: The current analysis demonstrates that engagement with a digitally delivered clinic waiting room educational intervention was high, providing explanation for its efficacy in improving motivation to change cardiovascular risk behaviours. The high fidelity of delivery demonstrates potential for scaling of such interventions across waiting rooms. Recall bias and low response rate may bias self-reported engagement measures. TRIAL REGISTRATION NUMBER: ANZCTR12618001725257.