Abstract
Background: In November 2018 the US Food and Drug Administration announced restrictions on e-cigarette manufacturers in response to a perceived epidemic of e-cigarette use among high school students. The stimulus was headline figures from the 2018 National Youth Tobacco Survey (NYTS). We analyse e-cigarette use and dependence in the NYTS in relation to lifetime history of use of tobacco products. Design and setting: Nationally representative survey of high school students in 2017 and 2018. Participants: 10,186 students in 2017 and 10,991 in 2018. Measurements: Any use of e-cigarettes in past 30 days, frequent e-cigarette use (≥20 of past 30 days) and indicators of dependence (craving in past 30 days; use within 30 minutes of waking and days used in lifetime) were analysed in relation to lifetime tobacco product use history, ranging from never use through to lifetime smoking of >100 cigarettes. Findings: Past-30-day e-cigarette use increased by 78% from 11.7% in 2017 to 20.8% in 2018. In both years, use was strongly associated with lifetime tobacco use history: it was seen in 8.4% of never tobacco users in 2018, in 29.0% of those who had tried a non-combustible, but never a combustible, product (OR 4.4 (CI 2.8-7.2) by comparison with never tobacco users), and in 71.0 % of those who had smoked more than 100 cigarettes in their lifetime (OR 26.8, CI 17.7-40.5) Frequent use occurred in 0.1% of never tobacco users in 2017 and 1.0% in 2018. Findings from 2014 and 2015 showed that first product tried was overwhelmingly cigarettes among those with a substantial lifetime cigarette history. Among past-30-day e-cigarette users who had never tried tobacco products in 2018, 3.8% reported craving, 3.1% reported wanting to use within 30 minutes of waking, and 61.8% said they had used e-cigarettes on ≤10 days in their life. Conclusions: Data from the NYTS do not support claims of a new epidemic of nicotine addiction stemming from use of e-cigarettes, nor concerns that declines in youth tobacco addiction stand to be reversed after years of progress. Among current e-cigarette users who had never tried tobacco products, responses consistently pointed to minimal dependence.