Peer-Led Digital Health Lifestyle Intervention in a Low-Income Community at Risk for Cardiovascular Disease (MYCardio-PEER): Mixed Methods Development and Process Evaluation Study

Background: Low-income populations in Malaysia face significant barriers to cardiovascular disease (CVD) prevention, including limited access to health information, preventive services, and ongoing support for behavior change. Digital health technologies present scalable opportunities for promoting heart-healthy behaviors, especially when integrated with community-based peer support. Objective: This study aimed to describe the development and process evaluation of MYCardio-PEER (Peer-led digital health lifestyle intervention for CVD prevention in a low-income Malaysian community), designed to empower adults at risk for CVD through mobile technology and community-based peer engagement. Methods: MYCardio-PEER was developed using the Medical Research Council Framework for Developing and Evaluating Complex Interventions, which included evidence synthesis, theory application, intervention planning, and content design. A 2-round Delphi method was used to conduct content validation involving 10 experts and community panel members, assessing relevance, clarity, and cultural appropriateness. The final intervention was delivered over 8 weeks and included bite-sized educational videos and infographics, and peer-led interactive activities. A pre-post feasibility trial was conducted in Kulim, Kedah, with 30 adults identified as having moderate to high CVD risk. Outcome measures included anthropometric and clinical parameters, dietary intake, and physical activity. A process evaluation assessed participant adherence and program satisfaction, and correlations with health outcomes. Results: Participants (18/30, 60.0% male, mean age 58.2, SD 6.7 years) showed significant reductions in CVD risk score, systolic blood pressure, total cholesterol, and low-density lipoprotein cholesterol. Physical activity levels and selected dietary behaviors improved post intervention. Program adherence was high, with 82.4% of participants completing all peer-led sessions. Satisfaction with program content (85.7%) and peer leadership (96.0%) was strong. Participants described the content as accessible, engaging, and relevant to their daily lives. Conclusions: MYCardio-PEER was developed and content-validated as a peer-led digital health lifestyle intervention for a low-income community at risk of CVD. Process evaluation showed good feasibility and acceptability, with encouraging pre-post improvements in behaviors and selected health indicators. These findings suggest the potential of integrating peer support with culturally adapted digital content in community-based CVD prevention.