Behavioral and psychosocial predictors of e-cigarette use in rural Thailand: A cross-sectional propensity score-matched study

INTRODUCTION: E-cigarette use in rural Thailand persists despite legal prohibition since 2014, with inadequate enforcement and misconceptions about safety driving its widespread adoption. Previous studies have documented usage patterns but have not examined in sufficient detail how demographic and psychosocial factors influence regulatory non-compliance in rural contexts. The aim of this study was to examine the behavioral and psychosocial determinants of e-cigarette use among rural Thai people. METHODS: This cross-sectional study (August-October 2025) examined e-cigarette use determinants among 1020 rural Thai participants aged ≥16 years recruited through multi-stage cluster sampling from rural northeastern Thailand. Data were collected using validated self-administered questionnaires. Multiple analytical approaches were applied (traditional regression, propensity score matching, inverse probability weighting, stratification, doubly robust estimation) to examine associations between exposures and e-cigarette use. E-value analyses were applied to quantify robustness to unmeasured confounding. Statistical significance was set at p<0.05. RESULTS: Males (adjusted odds ratio, AOR=5.29; 95% CI: 3.56-7.89) and females (AOR=4.59; 95% CI: 3.02-6.96) demonstrated substantially higher e-cigarette use likelihood versus LGBTQA+ individuals. Alcohol consumption showed associations (AOR=2.05; 95% CI: 1.53-2.74), with significant gender interaction (p=0.042). Low family support increased likelihood (AOR=1.98; 95% CI: 1.22-3.22), while high social support also showed increased association (AOR=2.05; 95% CI: 1.99-4.23). Knowledge exhibited U-shaped patterns, while perceived lax enforcement increased use (AOR=1.52; 95% CI: 1.10-2.10). Effect estimates demonstrated consistency across all propensity score methods. CONCLUSIONS: Gender, alcohol consumption, family dynamics, and enforcement perceptions significantly determined e-cigarette use in rural Thailand. These findings suggest the need for further research to establish causal relationships and inform the development of gender-stratified, family-based interventions. Methodological triangulation through propensity score approaches strengthened confidence in the observed associations.