TABLE 1

Progression From Cigarette Experimentation to Established Smoking, According to Baseline E-cigarette Use

nWeighted % With OutcomeUnadjustedAdjustedaAdjustedb
OR (95% CI)POR (95% CI)POR (95% CI)P
Outcome: smoked 100 cigarettes
 Wave 1 predictors
  E-cigarette never6469.7ReferenceReferenceReference
  E-cigarette ever58219.32.23 (1.55–3.21)<.0012.07 (1.41–3.04)<.0011.57 (0.99–2.49).05
  E-cigarette never6469.7ReferenceReferenceReference
  E-cigarette former40618.62.13 (1.43–3.18)<.0012.04 (1.33–3.12).0011.55 (0.94–2.56).09
  E-cigarette in the past 30 d17121.52.56 (1.58–4.14)<.0012.22 (1.31–3.74).0031.69 (0.93–3.05).08
Outcome: smoked during the past 30 d
 Wave 1 predictors
  E-cigarette never69926.6ReferenceReferenceReference
  E-cigarette ever59638.81.75 (1.35–2.27)<.0011.65 (1.26–2.15)<.0011.32 (0.99–1.76).06
  E-cigarette never69926.6ReferenceReferenceReference
  E-cigarette former41536.11.56 (1.15–2.12).0041.48 (1.09–2.02).011.20 (0.86–1.68).29
  E-cigarette in the past 30 d17645.32.29 (1.64–3.19)<.0012.10 (1.47–2.99)<.0011.64 (1.12–2.41).01
Outcome: smoked 100 cigarettes and smoked during the past 30 d
 Wave 1 predictors
  E-cigarette never6447.1ReferenceReferenceReference
  E-cigarette ever58015.62.43 (1.55–3.80)<.0012.23 (1.39–3.59)<.0011.80 (1.04–3.12).03
  E-cigarette never6447.1ReferenceReferenceReference
  E-cigarette former40615.52.41 (1.46–3.97)<.0012.29 (1.35–3.89).0021.85 (1.02–3.36).04
  E-cigarette in the past 30 d17116.32.56 (1.52–4.32)<.0012.19 (1.24–3.88).0071.76 (0.92–3.37).09
  • ORs and CIs corresponding to model covariates are shown in Supplemental Table 2. —, not applicable.

  • a Model covariates include the following: sex, age, and race and/or ethnicity.

  • b Model covariates additionally include the following: parent education, urban residence, household tobacco use, alcohol ever use, tobacco advertisement receptivity, sensation-seeking score, cigarette warning label exposure, interview time of year, and ever use of any other tobacco product.