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

Mark Conner,Ruth Simms‐Ellis,Christopher J Armitage,Sarah Grogan,Kamran Siddiqi,Robert West,Lisa Cowap,Anna‐Marie Marshall

doi:10.1111/add.15386

Abstract

Background and aimsAssociation of electronic cigarette use and subsequent smoking has received considerable attention, although age of first use has not. This study tested differences in regular (e‐cigarettes, cigarettes) and ever (cigarettes) use between e‐cigarette user groups: early versus never users, late versus never users, early versus late users and effects of controlling for covariates.DesignProspective study with 12‐ and 24‐month follow‐up of e‐cigarette/cigarette ever/regular use with data from an intervention.SettingForty‐five schools in England (Staffordshire and Yorkshire).ParticipantsNever smokers (3289 13–14‐year‐olds) who were part of a cluster randomized controlled trial.MeasurementsThe 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.FindingsEarly and late users compared with never users were significantly more likely to be regular e‐cigarette users [early: odds ratio (OR) = 9.42, 95% confidence interval (CI) = 5.38, 16.49, P < 0.001; late: OR = 6.89, 95% CI = 4.11, 11.54, P < 0.001], ever cigarette users (early: OR = 7.96, 95% CI = 6.02, 10.53, P < 0.001; late: OR = 5.13, 95% CI = 3.85, 6.84, P < 0.001) and regular cigarette users (early: OR = 7.80, 95% CI = 3.99, 15.27, P < 0.001; late: OR = 4.34, 95% CI = 1.93, 9.77, P < 0.001) at age 15–16 years. Late users compared with early users had significantly lower rates of ever use of cigarettes at 15–16 years (OR = 0.48, 95% CI = 0.35, 0.66, P < 0.001), although this difference was non‐significant at 12 months after first use of e‐cigarettes (OR = 0.89, 95% CI = 0.64, 1.25, P = 0.498). Controlling for covariates did not change the findings.ConclusionsAdolescents 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, a difference that may be attributable to a longer period of time to initiate cigarette use in former group.

Highlights

An increasing number of studies have assessed the impact of using e-cigarettes on subsequent initiation of smoking in adolescents
Few of the studies examining the relationship between e-cigarette use and subsequent smoking have examined the role of age of uptake of e-cigarettes
Two comparisons between early users and late users were possible here we focus on the former: comparisons at a specific age point, i.e., wave 5; comparisons on effects 12 months after e-cigarette use first reported

Summary

Introduction

An increasing number of studies have assessed the impact of using e-cigarettes on subsequent initiation of smoking in adolescents. McCabe et al [9] is one exception They reported data comparing US adolescents who began using e-cigarettes in the ninth grade (14-15 years or earlier) versus the 12th grade (17-18 years). Those adolescents who initiated e-cigarette use earlier compared to later were significantly more likely to become ever users of cigarettes (AOR = 2.83, 95%CI 1.06, 7.51) when high school seniors. The present research provides a further test of the impact of age of first reported use of e-cigarettes (i.e., early use versus late use) on subsequent ever cigarette use in a sample of UK adolescents.

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