Trends in adolescent smoking prevalence before and after the emergence of vaping in Australia: an interrupted time series analysis, 1999-2023.

Abstract

To compare adolescent smoking trends in Australia before and after the emergence of e-cigarettes in about 2010, to evaluate the potential impacts of adolescent vaping on smoking prevalence. Repeated cross-sectional study. Australian secondary schools. 172 406 students aged 12-17 years who took part in the Australian Secondary Students' Alcohol and Drug Survey between 1999 and 2023. Prevalence of ever, past year, past month and past week smoking for 12-17-year-olds, and daily smoking for 14-15-year-olds. From 2014 to 2022-2023, the prevalence of ever vaping among students increased 2.3-fold (from 13.2% to 29.9%), while past month vaping increased 4.8-fold (from 3.3% to 15.7%). From 1999 to 2022-2023, there were substantial declines in the prevalence of ever, past year, past month, past week and daily smoking among students, with reductions ranging between 74% and 89%. However, the rates of decline for these five measures of smoking slowed significantly from 2010 onwards, coinciding with the emergence of vaping. By 2022-2023, there were, respectively, 74 (95% confidence interval [CI], 67-80), 54 (95% CI, 48-60), 25 (95% CI, 21-29) and 16 (95% CI, 12-19) more 12-17-year-olds per 1000, and 7 (95% CI, 4-9) more 14-15-year-olds per 1000 who had engaged in ever, past year, past month, past week and daily smoking than projected by smoking trajectories from the pre-vaping era. These findings were robust to sensitivity analyses, including the use of different time series interruption points (change-years) and controlling for the affordability of cigarettes. Australia's remarkable progress in reducing adolescent smoking has slowed since the emergence of vaping, underscoring the need for integrated tobacco and vaping control strategies.