Short-term outcomes of Quebec’s ban on flavoured vaping products on adolescent electronic cigarette use: a 2022–2024 COMPASS longitudinal analysis

OBJECTIVES: Studies evaluating the outcomes of flavoured vaping product sales bans on adolescent vaping remain scarce, often inconclusive, and of limited generalizability, as they rely predominantly on US data. This study examines the short-term outcomes of such legislation implemented in Quebec (Canada) in October 2023. METHODS: A pretest-posttest design with a nonequivalent control group was used, drawing on data from the 2022, 2023 (pre-intervention), and 2024 (post-intervention) waves of the COMPASS study. The exposed group included 4540 adolescents from 68 Quebec schools, and the comparison group included 1491 adolescents from 39 Ontario schools. Indicators derived from self-reported current vaping (past-30-days) were analysed: non-use, daily use, initiation, reduction, mean magnitude of reduction, and cessation. RESULTS: Between 2023 and 2024, difference-in-differences analyses revealed no significant between-group differences across all six outcomes examined: non-use (-0.7 percentage point; 95% CI [-2.4, 1.1]), daily use (+ 0.6 point; [-0.2, 1.4]), initiation (+ 1.6 point; [-1.1, 4.3]), reduced use (-9.7 points; [-20.7, 1.3]), mean magnitude of use reduction (+ 0.3 points on the ordinal scale; [-0.1, 0.7]), and cessation (-3.6 points; [-14.9, 7.8]). CONCLUSION: The results do not provide evidence of short-term outcomes of the Quebec legislation and suggest the need for adjusted approaches. Such adjustments may involve strengthening both the design and implementation of interventions. Future research with longer follow-up periods is needed to identify the most effective measures to protect adolescents.