Ethnic and sex differences in E-cigarette use and relation to alcohol use in California adolescents: the California Health Interview Survey.

OBJECTIVES: E-cigarette use is not only prevalent among adolescents but is growing at an alarming rate. This study sought to determine e-cigarette use prevalence and its relation to alcohol use as a potential gateway drug, and how this may differ by sex and ethnicity in a multi-ethnic sample of California adolescents.

STUDY DESIGN: Cross-sectional survey.

METHODS: We included data from 1806 adolescents (weighted to 3.0 million) aged 12-17 in the 2014 and 2015 California Health Interview Survey (CHIS) cycles. The prevalence of e-cigarette use was calculated within sex and ethnic groups and the prevalence of alcohol use according to e-cigarette use was also examined with sample weighting providing population estimates. Multiple logistic regression models were built to predict the odds of using alcohol from e-cigarette use status adjusted for sociodemographic and other characteristics.

RESULTS: The prevalence of e-cigarette use was 9.1% (projected to 0.3 million) overall in California adolescents but highest in boys among non-Hispanic Whites (15.1%) and in Asian girls (13.3%). Among e-cigarette users, 61.3% of boys and 71.0% of girls reported using alcohol as well. The logistic regression odds of alcohol use, adjusted for age, ethnicity, body mass index, cigarette smoking status, socioeconomic status, parents' education level, and insurance status among e-cigarettes users (compared with non-users) was 9.2 in girls and 3.1 in boys (both P < 0.01). Asians/others, non-Hispanic whites and Hispanics were similarly at increased odds: 17.8, 5.4, and 3.0, respectively (P < 0.01 for Asians/others and for whites) of using alcohol compared with their non-e-cigarette using counterparts, respectively.

CONCLUSION: Attention needs to be paid to the high prevalence of e-cigarette smoking as well as its potential as a gateway drug for alcohol drinking in adolescents, especially among girls and Asians.