Adolescent E-Cigarette, Hookah, and Conventional Cigarette Use and Subsequent Marijuana Use.

Abstract

Adolescents from 10 public schools in Los Angeles, California, completed in-classroom surveys at baseline (fall 2013, ninth grade) and at a 24-month follow-up (fall 2015, 11th grade). Among adolescents who never used marijuana at baseline (N = 2668), associations of baseline e-cigarette, hookah, or combustible cigarette use with ever marijuana use (initiation), current marijuana use (past 30 days), and current dual use of marijuana and these tobacco products at the 24-month follow-up were examined. Baseline ever versus never e-cigarette use was associated with initiation (odds ratio [OR] 3.63; 95% confidence interval [CI] 2.69-4.90) and current (OR 3.67; 95% CI 2.51-5.36) marijuana use 24 months later. Ever versus never hookah use was associated with initiation (OR 3.55; 95% CI 2.49-5.08) and current (OR 4.10; 95% CI 2.69-6.25) marijuana use 24 months later. Similar associations were observed for combustible cigarette smoking and initiation (OR 4.30; 95% CI 2.79-6.63) and current use of marijuana (OR 1.97; 95% CI 1.05-3.68). Current use of any of these tobacco products at baseline was associated with current use of both tobacco and marijuana (OR 2.28; 95% CI 1.47-3.55) 24 months later. The association between tobacco use and subsequent marijuana use across adolescence extends to multiple tobacco products.