Table 3

Prevalence of past 12-month smoking at 1-year follow-up among 12th grade students who had ever smoked, by baseline vaping status (SEs and 95% relative risk CIs in brackets)†

AllNon-recent smoking at 12th grade survey‡Recent smokers at 12th grade survey‡
n (weighted)1016635
Recently vaped at time of 12th grade survey
 No37.44 (6.73)27.45 (6.78)76.93 (13.72)
 Yes80.18 (5.78)62.70 (10.62)94.86 (3.69)
Bivariate relative risk§2.14** (1.46 to 3.14)2.28** (1.27 to 4.10)1.23 (0.87 to 1.73)
Adjusted relative risk§2.15* (1.49 to 3.12)*2.26** (1.22 to 4.18)1.32 (0.89 to 1.96)
  • *p<0.05; **p<0.01.

  • †Estimates weighted.

  • ‡Non-recent smoking defined as youth who smoked at some time in the past but not in 30 days prior to the 12th grade survey, and recent smokers defined as those who smoked in the 30 days prior to the 12th grade survey.

  • §Differences across e-cigarette use groups modelled in a binomial regression with a log link. Not all controls could be included in each adjusted model due to convergence issues; see online supplementary table A4 for detailed presentation of multivariable models.