BACKGROUND Identifying young people who are susceptible to e-cigarettes is important for developing interventions designed to discourage uptake. Current evidence in a broader range of national contexts is needed given recent surges in youth e-cigarette use in many countries and the constantly evolving nature of vaping products and the promotional strategies used by the industry to increase their appeal.

METHODS A cross-sectional online survey was administered to around 1000 15-30 year olds in each of four countries: Australia, China, India, and the United Kingdom (total n = 4007). The survey assessed demographic characteristics, e-cigarette and tobacco use, exposure to e-cigarette advertising, and number of friends and family members who vape. Those who had never used e-cigarettes (n = 1589) were assessed for susceptibility (curiosity about e-cigarettes, intentions to use in the next 12 months, and likely use if offered by a friend). Mixed effects logistic regression analysis was used to identify factors associated with susceptibility to e-cigarette use.

RESULTS Susceptibility to e-cigarette use was apparent among 54% of respondents from Australia, 61% from India, 62% from the UK, and 82% from China. Factors positively associated with susceptibility were tobacco use, exposure to advertising, higher income, and having friends and family members who vape. Factors negatively associated with susceptibility were perceptions of harmfulness and education.

CONCLUSION The results indicate the need across a diverse range of countries for interventions designed to address substantial proportions of young people who are likely to be susceptible to e-cigarette use.