Effects of a self-management program based on self-efficacy theory on cardiovascular disease prevention behaviors among village health volunteers with metabolic syndrome: a quasi-experimental study

Metabolic syndrome increases cardiovascular disease (CVD) risk. Village health volunteers play a key role in community health promotion in Thailand; however, many also experience metabolic syndrome. Strengthening self-management through theory-based programs may improve health behaviors and support their role as community health role models. This study aimed to evaluate the effects of a self-management program based on self-efficacy theory on self-management behaviors for CVD prevention, anthropometric outcomes, and CVD risk among village health volunteers with metabolic syndrome. This quasi-experimental study employed a two-group pretest–posttest design. A total of 73 village health volunteers from Pathum Thani Province, Thailand, were allocated at the health-promotion-hospital level to the intervention group ( n = 38) or control group ( n = 35). The intervention group received a 12-week self-management program based on Bandura’s self-efficacy theory, whereas the control group received routine care. The primary outcome was self-management behaviors for CVD prevention; secondary outcomes were body weight, BMI, waist circumference, and Framingham 10-year CVD risk. Within-group change in the primary outcome was assessed using a paired-samples t-test. Baseline-adjusted ANCOVA was used for between-group comparisons when model assumptions were met, with rank-based change-score analysis otherwise. After baseline adjustment, the intervention group had higher post-intervention self-management behavior scores than the control group (adjusted mean difference 5.10 points, 95% CI 0.31–9.90; p = .037). Body weight (mean difference − 1.12 kg, 95% CI − 1.75 to − 0.50; p = .001), BMI (− 0.39 kg/m², 95% CI − 0.68 to − 0.09; p = .012), and waist circumference (− 1.97 cm, 95% CI − 3.19 to − 0.76; p = .002) were lower in the intervention group. Changes in Framingham 10-year CVD risk did not differ significantly between groups ( p = .494). The findings provide exploratory evidence that the program may be associated with improved self-management behaviors and short-term anthropometric outcomes. No between-group difference in CVD risk change was observed. Because study condition was confounded with hospital site, the observed differences cannot be attributed solely to the intervention and require confirmation in multi-site studies. Thai Clinical Trials Registry (TCTR20260123001). Retrospectively registered on 23 January 2026.