Prevalence And Predictors Of E-Cigarette Use Among Adolescents In Southeast Asia: A Systematic Review And Meta-Analysis

Abstract

Background: Adolescent e-cigarette use is rising across Southeast Asia, a region combining high combustible-tobacco prevalence, aggressive marketing, and sharply divergent national regulation. Evidence has accumulated rapidly since the last regional synthesis closed its search in 2021, but no meta-analytic estimate of prevalence exists for the contemporary period.

Methods: Following PRISMA 2020 guidelines, PubMed/MEDLINE was searched for observational studies published between January 2021 and July 2026 reporting the prevalence of, or factors associated with, e-cigarette use among adolescents aged 10 to 19 years in Southeast Asian countries. Screening, extraction, and risk-of-bias appraisal (Joanna Briggs Institute checklists) were conducted by a single reviewer. Pooled current-use prevalence was estimated for nationally representative surveys using a random-effects model with the Freeman-Tukey double-arcsine transformation; heterogeneity was quantified with I². Because predictor definitions were heterogeneous, associations were synthesised using a structured effect-direction approach rather than pooled quantitatively.

Results: Nineteen studies from Thailand, Malaysia, Vietnam, and Indonesia were included. Among nationally representative surveys, the pooled prevalence of current e-cigarette use was 4.5% (95% CI: 1.9–8.1%), with very high heterogeneity (I² = 99.4%), reflecting a genuine gradient from Vietnam (2.6%) to Malaysia (9.1%). Predictors were consistent in direction across studies: current cigarette smoking showed the strongest association (adjusted odds ratios 4.95–12.55), followed by alcohol and other substance use, peer or close-friend use, advertising and media exposure, male sex, and susceptibility among never-users. These predictors recurred across countries with opposite regulatory regimes, from comprehensive bans to permissive regulation.

Conclusions: Current e-cigarette use among Southeast Asian adolescents is common but highly heterogeneous between countries, whereas its predictors are strikingly consistent and predominantly social and behavioural. The stability of predictors across divergent regulatory contexts indicates that prevention should target the social and commercial pathways driving use, not rely on product legality alone. The extreme heterogeneity in prevalence underscores the need for harmonised, standardised surveillance.