Table 3.
Association of baseline e-cigarette use with current combustible smoking frequency and intensity at follow-up in relapsers, by baseline duration of smoking abstinence.
| E-cigarette Use at Baseline | Number of days smoked cigarettes in past 30 days at follow-up (smoking frequency) |
Number of cigarettes smoked per day on smoking day in past 30 days at follow-up (smoking intensity) |
||||
|---|---|---|---|---|---|---|
| Mean (95%CI)a | Unadjusted Coefficient (95% CI)b | Adjusted Coefficient (95% CI)c | Mean (95%CI)a | Unadjusted Coefficient (95% CI)b | Adjusted Coefficient (95% CI)c | |
| In those quit smoking within the prior 12 months at baseline (n = 335) | ||||||
| Never use (n = 85) | 21.3(18.1 to 24.4) | Reference | Reference | 7.1(5.0 to 9.2) | Reference | Reference |
| Prior use (n = 156) | 20.5(18.9 to 22.2) | −0.73 (−4.27 to 2.82) | −0.68 (−3.83 to 2.47)d | 7.7(6.3 to 9.1) | 0.56 (−1.81 to 2.93) | −1.47 (−3.49 to 0.55)d |
| Current occasional use (n = 30) | 20.1(15.2 to 25.0) | −1.15 (−7.22 to 4.92) | −1.79 (−7.79 to 4.20)d | 6.2(4.2 to 8.2) | −0.95 (−3.80 to 1.90) | −1.76 (−3.89 to 0.37)d |
| Current regular use (n = 64) | 22.1(18.9 to 25.2) | 0.79 (−3.57 to 5.16) | −0.52 (−4.06 to 3.02)d | 8.8(7.1 to 10.4) | 1.62 (−1.02 to 4.27) | −0.78 (−3.02 to 1.45)d |
| In those who quit smoking longer than 12 months ago at baseline (n = 157) | ||||||
| Never use (n = 99) | 12.7(9.5 to 16.0) | Reference | Reference | 5.8(3.7 to 7.8) | Reference | Reference |
| Prior use (n = 84) | 14.7(11.2 to 18.2) | 1.97 (−2.94 to 6.89) | 1.28 (−4.09 to 6.65) | 5.8(3.5 to 8.1) | 0.01 (−3.36 to 3.37) | −1.60 (−4.96 to 1.75) |
| Current use (n = 26)e | 12.6(6.2 to 18.9) | −0.17 (−7.09 to 6.75) | 0.48 (−6.65 to 7.60) | 6.1(3.0 to 9.3) | 0.38 (−3.13 to 3.89) | −0.30 (−4.30 to 3.69) |
Estimates weighted to reflect the sociodemographic population in the 2010 Census.
Estimate of association in univariable linear regression model.
Estimate of association in multivariable linear regression model adjusting for baseline age, sex, race/ethnicity, education, poverty, health insurance, region, years of regular smoking, cigarettes smoked per day when smoking, and time since quit smoking as covariates (estimates for covariates not shown).
Additionally adjusted for covariates available in recent quitters only, including use of pharmacotherapy, counseling, or social support as a cessation aid, and Wisconsin Inventory of Smoking Dependence Motives tobacco dependence score (estimates for covariates not presented).
Current use (occasional and regular use collapsed into singe groups due to low frequencies).