Association of Electronic Cigarette Use by US Adolescents With Subsequent Persistent Cigarette Smoking

Abstract

ImportanceMany studies have reported a positive association of youth electronic cigarette (e-cigarette) use with subsequent cigarette smoking initiation, but it remains unclear whether e-cigarette use is associated with continued cigarette smoking after initiation.ObjectiveTo assess the association of youth baseline e-cigarette use with their continued cigarette smoking 2 years after initiation.Design, Setting, and ParticipantsThe Population Assessment of Tobacco and Health (PATH) Study is a national longitudinal cohort study. This sample consisted of youth who participated in waves 3, 4, and 5 of the study (wave 3 was from October 2015 to October 2016, wave 4 was from December 2016 to January 2018, and wave 5 was from December 2018 to November 2019) and had never used cigarettes (cigarette-naive) by wave 3. The current analysis used multivariable logistic regressions in August 2022 to assess the association between e-cigarette use among cigarette-naive adolescents aged 12 to 17 years in 2015 and 2016 and subsequent continued cigarette smoking. PATH uses audio computer-assisted self-interviewing and computer-assisted personal interviewing to collect data.ExposuresEver and current (past 30-day) use of e-cigarettes in wave 3.Main Outcomes and MeasuresContinued cigarette smoking in wave 5 after initiating smoking in wave 4.ResultsThe current sample included 8671 adolescents who were cigarette naive in wave 3 and also participated in waves 4 and 5; 4823 of the participants (55.4%) were aged 12 to 14 years, 4454 (51.1%) were male, and 3763 (51.0%) were non-Hispanic White. Overall, regardless of e-cigarette use, few adolescents (362 adolescents [4.1%]) initiated cigarette smoking at wave 4, and even fewer (218 participants [2.5%]) continued smoking at wave 5. Controlling for multiple covariates, the adjusted odds ratio of baseline ever e-cigarette use, compared with never e-cigarette use, was 1.81 (95% CI, 1.03 to 3.18) for continued smoking measured as past 30-day smoking at wave 5. However, the adjusted risk difference (aRD) was small and not significant. The aRD was 0.88 percentage point (95% CI, −0.13 to 1.89 percentage points) for continued smoking, with the absolute risk being 1.19% (95% CI, 0.79% to 1.59%) for never e-cigarette users and 2.07% (95% CI, 1.01% to 3.13%) for ever e-cigarette users. Similar results were found using an alternative measure of continued smoking (lifetime ≥100 cigarettes and current smoking at wave 5) and using baseline current e-cigarette use as the exposure measure.Conclusions and RelevanceIn this cohort study, absolute and relative measures of risks yielded findings suggesting very different interpretations of the association. Although there were statistically significant odds ratios of continued smoking comparing baseline e-cigarette users with nonusers, the minor risk differences between them, along with the small absolute risks, suggest that few adolescents are likely to continue smoking after initiation regardless of baseline e-cigarette use.

e-Cigarette and Cigarette Use Among Youth: Gateway or Common Liability?

“…Given that cigarettes are overwhelmingly responsible for most tobacco-caused morbidity and mortality, addressing this research gap seems paramount. In this study, Sun and colleagues explore this important question and considered a variety of cigarette smoking patterns, as well as differences in absolute risk. Using data from the Population Assessment on Tobacco Use and Health (PATH) longitudinal cohort study, Sun et al studied more than 8000 cigarette-naive youths from waves 3 to 5.…”

“…In this study, Sun and colleagues explore this important question and considered a variety of cigarette smoking patterns, as well as differences in absolute risk. Using data from the Population Assessment on Tobacco Use and Health (PATH) longitudinal cohort study, Sun et al studied more than 8000 cigarette-naive youths from waves 3 to 5. They found that youths who had used e-cigarettes at baseline (wave 3) had higher odds of continued cigarette smoking, but the absolute risks of continued smoking at wave 5 were very small and did not significantly differ by baseline e-cigarette use.…”

“…They found that youths who had used e-cigarettes at baseline (wave 3) had higher odds of continued cigarette smoking, but the absolute risks of continued smoking at wave 5 were very small and did not significantly differ by baseline e-cigarette use. Moreover, the prevalence of frequent smoking, defined as 20 or more days in the past 30 days, 2 years later (wave 5) was so low (0.2%), the authors could not model this outcome due to its rarity . In other words, while e-cigarette use was associated with future cigarette smoking, the pattern of cigarette smoking itself was not clinically meaningful.…”

“…The research from Sun et al, also highlights some important lessons for researchers, clinicians, and policy makers. First, the conventional operational definitions for ever and current use of tobacco differ for youths and adults .…”

“…Likewise, current use (ie, past 30 days) for youths can also capture this range of use. Importantly, Sun et al considered a variety of continued cigarette use behaviors beyond experimentation that would reflect meaningful dose-response health consequences, such as established and frequent use. Future efforts examining the association between use of e-cigarettes or other tobacco products and cigarette smoking should focus on sustained patterns of use that are associated with detrimental health outcomes.…”