Adolescent e-Cigarette Use: Age-Varying Prevalence and Association with Traditional Cigarette Smoking

Introduction. Electronic cigarettes (e-cigarettes) have been touted by some as a safer alternative to traditional cigarette smoking, but emerging evidence shows that adolescents who use e-cigarettes are significantly more likely to also smoke traditional cigarettes. There is consistent evidence that the age of experimentation with tobacco products is associated with future dependence, with use in early adolescence (i.e., before age 15) being more strongly linked to addiction than use in later adolescence. However, few studies have been able to document how the prevalence and correlates of e-cigarette use vary with age across adolescence. The current study examines the prevalence of e-cigarette use, and its association with traditional cigarette smoking, as a complex function of age among adolescents aged 11-19.  

Method. Data come from the 2014 National Youth Tobacco Survey, a cross-sectional survey containing a nationally representative sample of middle- and high-school students in the United States (N=22,007). The analytic sample contained 21,798 adolescents between ages 11-19 (49% female; 48% White, 17% African-American, 29% Hispanic). Current traditional cigarette smoking and current e-cigarette smoking were assessed via the questions “During the past 30 days, on how many days did you [smoke cigarettes/use e-cigarettes]?” Time-varying effect models (TVEMs) were used to examine the age-varying prevalence rate of e-cigarette use and its age-varying association with cigarette smoking.

Results. The prevalence of e-cigarette use varied strongly by age. For the full sample, rates were lowest at ages 11 and 12, and increased steadily until age 16, when they plateaued at around 15%. Males were significantly more likely to use e-cigarettes than females from ages 14-17. Rates of e-cigarette use were significantly lower for African-American youth versus Hispanic youth from age 12 onward, and were significantly lower compared to White youth from age 14 onward. E-cigarette use for Hispanic youth was significantly higher than for White youth between ages 12-14. E-cigarette use was very strongly related to traditional cigarette smoking across all ages, and the strength of this association was significantly stronger in early versus mid-to-late adolescence. For example, adolescents using (versus not using) e-cigarettes at age 12 had 40 times higher odds of also smoking traditional cigarettes, whereas 16-year old adolescents using e-cigarettes had 15 times higher odds of smoking cigarettes. 

Conclusions. Our findings strongly suggest that e-cigarette use and traditional cigarette smoking go “hand-in-hand” among adolescents, and that e-cigarette use may be most strongly linked with traditional cigarette smoking during early adolescence, which is a well-known risk factor for adult nicotine dependence. Early e-cig use was highest among Hispanic adolescents, suggesting that these youth may be at high risk for future nicotine dependence. Findings suggest that prevention programs may need to target both e-cig use and traditional cigarette smoking in order to prevent long-term tobacco-related problems in youth.