Patterns of e-cigarette use by sex and age in Thailand: The National Health Examination Survey 2024–2025

INTRODUCTION: Since their introduction in the early 2000s, the prevalence of e-cigarette use has increased globally. E-cigarette use among females, while usually lower than that of males, is rising and typically higher than cigarette use. This study describes the prevalence of e-cigarette use in Thailand stratified by age and sex, including frequency of use, place obtained, preferred flavors, and reasons for use. METHODS: This cross-sectional study used the seventh Thai National Health Examination Survey (NHES), conducted between 2024 and 2025. Weighted percentages with 95% confidence intervals (CIs) were used to describe self-reported e-cigarette use patterns across age groups and sex, accounting for survey weights and the complex survey design. We also used multivariable logistic regression models to examine the factors associated with e-cigarette use. RESULTS: Current e-cigarette use was highest among males aged 20-29 years (13.4%; 95% CI 10.7-16.1). Among current e-cigarette users, dual use was higher among males than females (50.3%; 95% CI: 45.1-55.5 vs 18.8%; 95% CI: 11.7-26.0; p<0.01). Never smoking cigarettes among participants who currently use e-cigarettes was higher among females <30 years than males (64.7%; 95% CI: 55.4-74.1 vs 22.5%; 95% CI: 17.4-27.6; p<0.001). Fruit flavors were the most preferred among e-cigarette users across age groups and sexes. Females were more likely to use e-cigarettes to relieve stress and generally initiated using e-cigarettes at a younger age than males. Multivariable logistic regression revealed that age and sex were significantly (p<0.001) associated with ever, current, and daily e-cigarette use. CONCLUSIONS: This study describes patterns of e-cigarette use in a country where e-cigarettes are prohibited. The high proportion of dual use and the high prevalence of e-cigarette use among younger adults who never smoked, suggest that e-cigarette use is not primarily motivated by cessation among younger users. Health initiatives should dispel e-cigarette harm reduction claims and denormalize social norms that encourage their use.