TABLE 3

Age-Stratified Analysis of the Temporal Association Between E-cigarette Ever Use at Wave 1 and Marijuana Use at Wave 2 Among Baseline Marijuana Never Users, PATH Study, 2013–2015

Marijuana Never Users at Wave 1E-cigarette Ever Use at Wave 1Marijuana P12M Use at Wave 2Marijuana Heavy Use at Wave 2
nWeighted % (95% CI)aORanWeighted % (95% CI)aORa
Aged 12–14 (n = 5901)bNo (n = 5703)3215.5 (4.9–6.2)REF1071.9 (1.5–2.3)REF
Yes (n = 177)5229.2 (23.0–36.2)2.7 (1.7–43)***2112.0 (7.6–18.5)2.5 (1.2-–5.3)*
Aged 15–17 (n = 4463)bNo (n = 4117)43810.6 (9.5–11.9)REF1383.4 (2.8–4.2)REF
Yes (n = 334)8525.3 (21.0–30.3)1.6 (1.2–2.3)**205.9 (3.8–9.1)0.9 (0.5–1.5)
Interaction between age group and e-cigarette ever usec2.1 (1.3–3.3)**3.1 (1.5–6.4)**
  • —, not applicable.

  • a For all models, aOR was adjusted by sensation seeking, ever use of cigarettes, drinking, nonmedical use of prescription drugs and other illicit drugs, and demographics (sex, race and/or ethnicity, grade performance, parental education, and region) at wave 1.

  • b Separate multivariable logistic regression models were performed for youth aged 12–14 years and youth aged 15–17 years, respectively.

  • c A joint model was constructed to evaluate the main effects of age and e-cigarette use, along with an interaction between age and e-cigarette use. Interaction aOR indicates that e-cigarette use (versus no use) at baseline was associated with higher risks of marijuana use at wave 2 among younger adolescents than among older adolescents.

  • * P < .05;

  • ** P < .01;

  • *** P < .001.