abstract
- BACKGROUND: Few studies have examined predictors of exclusive e-cigarette use, exclusive smoking and dual use among youth. We investigated whether frequency of e-cigarette use and cigarette smoking predicted involvement in different usage groups after a 1- and 2-year follow-up among a sample of Canadian youth. METHODS: A longitudinal sample of youth who participated in three waves of COMPASS [Wave 1 (W1) 2015/16, Wave 2 (W2) 2016-17, Wave 3 (W3) 2017/18] was identified (N = 5,704). Multinomial logistic regression was used to examine whether frequency of e-cigarette use and cigarette smoking at W1 predicted involvement in different usage groups at W2 and W3. Similarly, we examined whether changes in frequency of e-cigarette use and cigarette smoking between W1 and W2 predicted involvement in different usage groups at W3. RESULTS: E-cigarette users reporting use on 4 or more days per month at W1 had greater odds of dual use at W2, compared to non-users (aOR = 11.22, p < 0.0001). Those who reduced their frequency of e-cigarette use between W1 and W2 had lower odds of exclusive e-cigarette use and dual use at W3 (aOR = 0.18 and 0.17 respectively; both p < 0.05). Those who increased their frequency of cigarette smoking between W1 and W2 had higher odds of exclusive smoking and dual use at W3 (aOR = 22.65 and aOR = 9.92 respectively; both p < 0.0001). DISCUSSION: Reductions in frequency of e-cigarette use appeared to have a protective effect of reducing exclusive e-cigarette use and dual use at follow-up. Increases in frequency of cigarette smoking were a significant predictor of exclusive smoking and dual use.