Introduction

E-cigarette use by adolescents is an important issue for public health. This study analyzed the frequency of e-cigarette use and its association with smoking status among U.S. adolescents.

Methods

The National Youth Tobacco Survey 2015 was analyzed in 2017, focusing on frequency of past 30-day e-cigarette use according to smoking status of participants. Smoking status was classified as never smoker, ever/not a past 30-day smoker, and past 30-day smoker. Infrequent and frequent smoking and e-cigarette use was defined as use for <20 and ≥20 of the past 30 days, respectively.

Results

Past 30-day e-cigarette use was reported by 54.5% (95% CI=47.8%, 61.0%) of past 30-day smokers, 26.5% (95% CI=23.2%, 30.1%) of ever/not past 30-day smokers, and 4.6% (95% CI=4.0%, 5.2%) of never smokers ( p<0.001). No past 30-day e-cigarette use was reported by 94.5% and frequent e-cigarette use by 0.3% of never smokers. Past 30-day e-cigarette use was reported by 50.4% (95% CI=43.6%, 57.3%) of infrequent and 64.7% (95% CI=54.4%, 73.8%) of frequent past 30-day smokers ( p<0.001). E-cigarette use frequency correlated with both smoking status and tobacco cigarette consumption (ρ=0.42, p<0.001 and ρ=0.40, p<0.001, respectively). Past 30-day smokers were more likely to report past 30-day e-cigarette use (OR=11.42, 95% CI=9.06, 14.40) compared with adolescents reporting no past 30-day smoking.

Conclusions

E-cigarette use is more prevalent among ever and past 30-day smoking adolescents compared with never smoking adolescents. Frequent e-cigarette use is rare among never smoking adolescents.