Effectiveness and Feasibility of a BCW-Informed WeChat Text-Messaging Intervention to Improve Medication Adherence After PCI: A 12-Week Quasi-Experimental Study (Preprint)

<sec> <title>BACKGROUND</title> Medication nonadherence after percutaneous coronary intervention (PCI) remains a major barrier to secondary prevention. Prior SMS-based interventions have shown inconsistent results, often limited to reminders without addressing behavioral or psychological determinants. </sec> <sec> <title>OBJECTIVE</title> To evaluate the effectiveness and feasibility of a theory-informed, WeChat-based text-messaging program for improving adherence and patient-reported outcomes in post-PCI patients. </sec> <sec> <title>METHODS</title> A nonrandomized, quasi-experimental parallel-group study with a mixed-methods design was conducted from July 2022 to April 2023 at a tertiary hospital in Hangzhou, China. Patients were allocated by ward admission to intervention or control groups. The intervention comprised a 12-week WeChat program with daily medication reminders and educational messages mapped to COM-B domains and behavior change techniques. The primary outcome was adherence (MMAS-8); secondary outcomes were medication beliefs (BMQ-Specific), self-efficacy (SEAMS), and health status (SAQ). Outcomes were measured at baseline, discharge, and 12 weeks by blinded assessors. Analyses used ANCOVA with baseline adjustment and multiple imputation. After 12 weeks, semi-structured telephone interviews with intervention participants explored usability, message clarity and relevance, reminder helpfulness, timing and tone, and unmet needs. Interviews were conducted by an independent researcher, purposively sampled until thematic saturation, and thematically analyzed from verbatim transcripts. </sec> <sec> <title>RESULTS</title> Of 180 patients screened, 92 were enrolled and 87 (94.6%) completed follow-up. At 12 weeks, adherence was higher in the intervention group (adjusted mean MMAS-8, 7.38 vs 6.20; mean difference, 1.18 [95% CI, 0.95–1.41]; P&lt;.001). Secondary outcomes also favored the intervention, including improved beliefs, self-efficacy, and quality of life. Feasibility benchmarks were exceeded, with deliverability 97.9%, retention 95.7%, and acceptability scores &gt;8/10. Interviews confirmed usability and highlighted the need for personalization. </sec> <sec> <title>CONCLUSIONS</title> A theory-informed, WeChat-based program improved adherence, beliefs, self-efficacy, and quality of life after PCI. The intervention was feasible, acceptable, and scalable. Randomized trials are warranted to confirm long-term effectiveness and cost-effectiveness. </sec> <sec> <title>CLINICALTRIAL</title> Chinese Clinical Trial Registry (ChiCTR2200061353) https://www.chictr.org.cn/bin/project/edit?pid=172238 </sec>