Experimenting first with e‐cigarettes versus first with cigarettes and transition to daily cigarette use among adolescents: the crucial effect of age at first experiment

• Published in: Addiction (Abingdon, England) England), 2021-06, Vol.116 (6), p.1521-1531
• Main Authors: Legleye, Stéphane, Aubin, Henri‐Jean, Falissard, Bruno, Beck, François, Spilka, Stanislas
• Format: Article
• Language: English
• Subjects: Adolescents; Age; age at initiation; Bias; Cigarettes; Cultural factors; Drug abuse; Economic status; Electronic cigarettes; E‐cigarette; Life Sciences; propensity score; Risk reduction; Santé publique et épidémiologie; Smoking; Teenagers; Tobacco; Tobacco smoking; transition; Weighting
• ISSN: 0965-2140; 1360-0443
• DOI: 10.1111/add.15330

Background and aims Most studies in English‐speaking countries have found a positive association between e‐cigarette experimentation and subsequent daily tobacco smoking among adolescents. However, this result may not be valid in other cultural contexts; in addition, few studies have assessed whether this association varies with the subject' age at the time of e‐cigarette experimentation. This study aimed to estimate the association between experimenting first with e‐cigarette (rather than tobacco) and subsequent daily smoking according to age at the time of experimentation. Design Secondary analysis; risk ratios (RRs) computed using modified Poisson regressions with inverse probability weighting. Setting A cross‐sectional nation‐wide representative survey performed in 2017 in France. Participants French adolescents (n = 24 111), aged 17 to 18.5 years, who had previously experimented with either e‐cigarettes or tobacco. Measures Exposure was defined as the experimentation with e‐cigarettes first (whether or not followed by experimentation with tobacco); the outcome as daily tobacco smoking at the time of data collection. Gender, age, literacy, socio‐economic status, pre‐exposure repeat school years and experimentation with drunkeness, 3 licit and 8 illicit drugs were adjusted for. Uncertainties about the sequence of events defining exposure were handled by the definition of three patterns of exposure, to avoid a misclassification bias. Findings Exposure reduced the risk of transition to daily smoking: RR = 0.58, 95% confidence interval (CI) = 0.54, 0.62. This effect increased in a linear manner with age at exposure (RR = 0.87, 95% CI = 0.78; 0.98 for 1 year, P