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

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, a difference that may be attributable to a longer period of time to initiate cigarette use in former group.