Electronic Cigarettes Use and Intention to Cigarette Smoking among Never-Smoking Adolescents and Young Adults: A Meta-Analysis

Electronic cigarettes (e-cigarettes) use is becoming increasingly common, especially among adolescents and young adults, and there is little evidence on the impact of e-cigarettes use on never-smokers. With a meta-analysis method, we explore the association between e-cigarettes use and smoking intention that predicts future cigarette smoking. Studies were identified by searching three databases up to January 2016. The meta-analysis results were presented as pooled odds ratio (OR) with 95% confidence interval (CI) calculated by a fixed-effects model. A total of six studies (91,051 participants, including 1452 with ever e-cigarettes use) were included in this meta-analysis study. We found that never-smoking adolescents and young adults who used e-cigarettes have more than 2 times increased odds of intention to cigarette smoking (OR = 2.21, 95% CI: 1.86-2.61) compared to those who never used, with low evidence of between-study heterogeneity (p = 0.28, I² = 20.1%). Among never-smoking adolescents and young adults, e-cigarettes use was associated with increased smoking intention.