A social cognitive theory-based self-efficacy intervention with LINE follow-up on self-efficacy, health-promoting behaviours and body mass index among Myanmar migrants working in Bangkok, Thailand.

Migrant populations encounter barriers to healthy lifestyles, increasing their risk for non-communicable diseases (NCDs). A randomized controlled trial with two groups and repeated measures was carried out in four factories in Bangkok to evaluate the effectiveness of a Social Cognitive Theory-Based Self-Efficacy Intervention with LINE Follow-Up on self-efficacy, health promoting behaviours (HPBs), and body mass index (BMI). Sixty registered Myanmar migrants were randomly divided into an experimental group (n = 30) and a control group (n = 30). Measurements were taken at the baseline, Week 3, and Week 8. Data analysis was conducted using a two-way mixed repeated measures MANOVA with a significance level of α = 0.01. The results revealed a significant interaction effect between time and group for all dependent variables [F (6,53) = 11.84, P < .001, ηp2 = 0.57], indicating a significant difference in the trajectory of the three dependent variables between the intervention and control groups. The intervention group showed significantly greater improvements in HPBs [F (2,116) = 5.309, P = .006, ηp2 = 0.08] and BMI [F(1.711,99.232) = 34.846, P < .001, ηp2 = 0.375] compared to the control group over the 8-week period. A Self-Efficacy Intervention with LINE Follow-Up led to significant improvements in self-efficacy, HPBs, and BMI trajectory among Myanmar migrants. The smartphone-based LINE Official Account is a low-cost and practical tool for health promotion that reinforces self-efficacy through verbal persuasion and motivation, and it facilitates sustained HPBs that can influence BMI by continuous and accessible follow-up. This digital health strategy shows promise for enhancing health outcomes in this population and could potentially contribute to a healthier workforce and decreased burden of NCDs in the long term. Contribution to Health Promotion This paper outlines the strategies for supporting the implementation of a Social Cognitive Theory-Based Self-Efficacy Intervention with LINE Follow-Up.Stakeholder engagement is emphasized as crucial for the success of the programme, based on SCT.If the effectiveness of the intervention on HPBs is confirmed, the findings could inform nationwide programmes for migrants, potentially reducing NCDs and healthcare costs.From a health economic standpoint, this study contributes to promoting a healthy workforce in Thailand. The systematic approach used to develop the self-efficacy strategy can be applied to different contexts and interventions.