Importance: Banning electronic cigarette (e-cigarette) sales to minors has been a key policy to protect children from e-cigarettes in the United States and Canada, but to date little is known about the outcome of such a ban.
Objectives: To investigate the association of banning e-cigarette sales to minors in Canada with e-cigarette use among youths and the mechanisms through which a ban might be associated with their e-cigarette use.
Design, setting, and participants: This quasi-experimental difference-in-differences and triple-differences study used data from the nationally representative Canadian Tobacco, Alcohol and Drugs Survey (2013-2017) and Canadian Student Tobacco, Alcohol and Drugs Survey (2014-2017). Study samples consisted of respondents aged 15 to 18 years (in difference-in-differences analysis; n = 8212) and aged 15 to 25 years (in triple-differences analysis; n = 20 934) in the Canadian Tobacco, Alcohol and Drugs Survey, and students in grades 6 to 12 (in difference-in-differences analysis; n = 78 650) in the Canadian Student Tobacco, Alcohol and Drugs Survey.
Interventions: Canada's provincial bans on e-cigarette sales to youths younger than 18 or 19 years (depending on province) implemented between 2015 and 2017.
Main outcomes and measures: The primary outcome was past 30-day e-cigarette use among youths. Secondary outcomes were difficulty of access to e-cigarettes, perception of e-cigarette harm, and use of social sources of e-cigarettes.
Results: After the bans, e-cigarette use among youths increased in all provinces, but the increase was 3.1 percentage points (95% CI, 0.2-6.0; P = .04), or 79%, lower in provinces with a ban than in provinces without a ban. Youths in provinces with a ban were 2.6 percentage points (95% CI, 1.5-3.7; P = .001), or 18%, less likely to believe that regular e-cigarette use poses no harm and 6.2 percentage points (95% CI, 1.1-11.4; P = .02), or 16%, more likely to self-report greater difficulty in obtaining e-cigarettes. Among youths who reported using e-cigarettes, the likelihood of obtaining e-cigarettes from social sources was 17.3 percentage points (95% CI, 5.2 -29.4; P = .01), or 29%, higher in provinces with a ban. These findings were robust to several sensitivity analyses.
Conclusions and relevance: Banning e-cigarette sales to minors was associated with a significant reduction in the rate of increase in e-cigarette use by youths, but this policy alone could not reverse the overall increase in e-cigarette use. The findings from this study suggest that this policy should be supplemented with other measures that can reduce young people's desire to obtain e-cigarettes through social sources, such as a ban on e-cigarettes with flavors that appeal to youths and children.