Association between age at first reported e-cigarette use and subsequent regular e-cigarette, ever cigarette and regular cigarette use.

Introduction:
This article reports a study that aimed to examine the relationship between the age of first reported use of e-cigarettes and subsequent ever and regular cigarette use in a sample of UK adolescents. The study also explored the impact of early versus late use of e-cigarettes on subsequent regular e-cigarette use, ever cigarette use, and regular cigarette use.

Key points:

* The study used data from a cluster-randomized controlled trial of a school-based intervention to prevent smoking initiation in 45 schools in England.
* The sample consisted of never smokers aged 13-14 years who were part of the trial.
* The sample was divided into groups of e-cigarette users: early users (at 13-14 years), late users (at 14-15 years), and never users (at 13-14 and 14-15 years).
* Dependent variables were self-reported regular e-cigarette and cigarette use and ever cigarette use at 15-16 years.
* Covariates were assessed, including gender, ethnicity, individual/school-level socio-economic status, friends and family smoking, impulsivity and intentions, attitudes, norms, perceived behavioural control and self-efficacy in relation to smoking.
* Early and late users compared with never users were significantly more likely to be regular e-cigarette users, ever cigarette users, and regular cigarette users at age 15-16 years.
* Late users compared with early users had significantly lower rates of ever use of cigarettes at 15-16 years, although this difference was non-significant at 12 months after first use of e-cigarettes.

Main message:
The study suggests that adolescents in England who report using e-cigarettes at age 13-14 years have higher rates of subsequently initiating cigarette use than adolescents who report using e-cigarettes at age 14-15 years. The difference may be attributable to a longer period of time to initiate cigarette use in the former group. The study highlights the importance of regulating the marketing and sale of e-cigarettes to minors to prevent their use and potential progression to cigarette smoking.

Conner M, Grogan S, Simms-Ellis R, et al. Association between age at first reported e-cigarette use and subsequent regular e-cigarette, ever cigarette and regular cigarette use. Addiction (Abingdon, England). 2021;116(7):1839-1847. doi:10.1111/add.15386