Risk factors for e-cigarette, conventional cigarette, and dual use in German adolescents: a cohort study.

Objective: Little is known about risk factors that are associated with e-cigarette use in adolescents.

Methods: Multilevel mixed-effects regressions were performed to assess the relationship between factors that might be associated with e-cigarette, conventional cigarette and dual use in a cohort of 2693 German adolescents (mean age=12.5 years; SD=0.6). Risk factors were assessed in October 2010 and life time e-cigarette and conventional cigarette use were assessed 26 months later.

Results: Use of e-cigarettes as well as use of conventional cigarette and dual use were associated with higher sensation seeking scores, and higher odds of having friends and parents who smoke conventional cigarettes, with conventional cigarette use additionally with male gender, being older, having higher odds of siblings who smoke conventional cigarettes, and less likely for adolescents who attend a Gymnasium, secondary school with a strong emphasis on academic learning. The use of conventional cigarettes at baseline did not predict e-cigarette use at follow-up. Lifetime prevalence of e-cigarette use was 4.7%, of conventional cigarette use 18.4%. A quarter of e-cigarette users (23.8%) never smoked a conventional cigarette.

Discussion: Data indicate that e-cigarette and conventional cigarette use share many but not all risk factors. E-cigarettes could counteract the process of denormalization of smoking.