Table 4. Making a quit attempt and quitting smoking for ≥ 30 days by ENDS use and characteristics of ends use among all baseline smokers (N = 822) and baseline daily smokers (N = 613*).
| Made ≥ 1 Quit Attempt During Study | Not Smoking (≥30 days) at Follow-Up | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ENDS Use During 12-Month Study | Denom | Num | wt. % | 95% CI | AOR† | 95% CI | Denom | Num | wt. % | 95% CI | AOR† | 95% CI |
| No ENDS Use (Reference) | 486 | 197 | 44.2 | 37.32, 51.27 | REF | - | 486 | 83 | 22.2 | 16.70, 28.91 | REF | - |
| No ENDS Use (Reference–Daily Smokers) | 365 | 114 | 31.22 | 23.99, 39.49 | REF | - | 365 | 36 | 9.17 | 5.56, 14.77 | REF | - |
| Model 3a: ENDS Use Frequency | ||||||||||||
| Non-daily ENDS use | 282 | 146 | 59.7 | 50.36, 68.42 | 2.14 | 1.24, 3.69 | 283 | 19 | 7.5 | 4.01, 13.54 | 0.27 | 0.11, 0.64 |
| Daily ENDS use | 53 | 31 | 50.9 | 30.44, 71.11 | 0.93 | 0.32, 2.65 | 53 | 10 | 9.3 | 4.01, 20.26 | 0.17 | 0.04, 0.82 |
| Model 3b: ENDS Use Frequency (Daily Smokers) | ||||||||||||
| Non-daily ENDS use | 212 | 94 | 53.22 | 42.12, 64.02 | 2.56 | 1.37, 4.78 | 213 | 7 | 2.95 | 0.96, 8.66 | 0.29 | 0.08, 1.10 |
| Daily ENDS use | 35 | 20 | 53.87 | 30.30, 75.83 | 1.77 | 0.48, 6.50 | 35 | 9 | 13.03 | 5.19, 29.06 | 0.75 | 0.18, 3.13 |
| Model 4a: Importance of ENDS Use for Quitting Smoking | ||||||||||||
| None or low importance | 45 | 20 | 44.9 | 25.23, 66.37 | 1.35 | 0.45, 4.06 | 45 | 3 | 8.5 | 1.49, 36.02 | 0.16 | 0.03, 0.87 |
| Moderate to high importance | 245 | 130 | 60.8 | 50.85, 70.01 | 1.8 | 1.01, 3.21 | 246 | 25 | 8.1 | 4.48, 14.05 | 0.24 | 0.10, 0.59 |
| Model 4b: Importance of ENDS Use for Quitting Smoking (Daily Smokers) | ||||||||||||
| None or low importance | 29 | 12 | 31.74 | 13.42, 58.25 | 1.13 | 0.19, 6.71 | 29 | 1 | 1.19 | 0.14, 9.30 | 0.07 | 0.00, 1.22 |
| Moderate to high importance | 181 | 81 | 55.46 | 43.59, 66.73 | 2.38 | 1.23, 4.60 | 182 | 14 | 4.02 | 1.86, 8.49 | 0.30 | 0.10, 0.88 |
| Model 5a: ENDS Flavors | ||||||||||||
| Tobacco/unflavored | 95 | 42 | 48.9 | 32.32, 65.79 | 1.51 | 0.57, 3.96 | 96 | 3 | 2.7 | 0.64, 10.64 | 0.11 | 0.02, 0.50 |
| Menthol / Wintergreen / Mint | 57 | 33 | 60.6 | 37.76, 79.60 | 3.41 | 1.33, 8.71 | 57 | 7 | 6.37 | 2.22, 16.92 | 0.38 | 0.11, 1.36 |
| All other flavors (e.g., fruit, candy) | 174 | 97 | 60.86 | 49.52, 71.14 | 1.83 | 0.97, 3.48 | 174 | 17 | 8.75 | 4.43, 16.56 | 0.22 | 0.08, 0.59 |
| Model 5b: ENDS Flavors (Daily Smokers) | ||||||||||||
| Tobacco/unflavored | 78 | 30 | 41.59 | 23.88, 61.77 | 1.39a | 0.52, 3.76 | 79 | 1 | 1.05 | 0.14, 7.49 | 0.04 | 0.00, 0.86 |
| Menthol / Wintergreen / Mint | 42 | 25 | 66.39 | 37.38, 86.73 | 6.02a | 2.28, 15.91 | 42 | 5 | 4.73 | 1.40, 14.84 | 0.46 | 0.10, 2.11 |
| All other flavors (e.g., fruit, candy) | 119 | 55 | 54.48 | 40.89, 67.43 | 2.36 | 1.13, 4.96 | 119 | 8 | 3.68 | 1.20, 10.76 | 0.32 | 0.09, 1.11 |
| Model 6a: ENDS Device Type | ||||||||||||
| Tank ENDS | 116 | 59 | 53.7 | 38.86, 67.91 | 1.53 | 0.73, 3.19 | 117 | 11 | 11.1 | 4.85, 23.44 | 0.39 | 0.12, 1.27 |
| Cartridge ENDS | 149 | 80 | 60.76 | 47.57, 72.55 | 1.96 | 1.02, 3.75 | 149 | 12 | 5.45 | 2.21, 12.84 | 0.16 | 0.05, 0.48 |
| Disposable/Other ENDS | 70 | 38 | 62.06 | 44.10, 77.23 | 2.51 | 0.85, 7.38 | 70 | 6 | 6.4 | 2.16, 17.46 | 0.24 | 0.05, 1.05 |
| Model 6b: ENDS Device Type (Daily Smokers) | ||||||||||||
| Tank ENDS | 86 | 39 | 51.78 | 34.78, 68.38 | 2.16 | 0.89, 5.27 | 87 | 6 | 5.46 | 1.60, 17.06 | 0.49 | 0.11, 2.28 |
| Cartridge ENDS | 113 | 52 | 50.92 | 35.97, 65.70 | 2.26 | 1.07, 4.78 | 113 | 8 | 2.82 | 1.15, 6.74 | 0.19 | 0.04, 0.87 |
| Disposable/Other | 48 | 23 | 60.04 | 37.76, 78.82 | 3.18 | 1.06, 9.51 | 48 | 2 | 4.27 | 0.69, 22.32 | 0.49 | 0.08, 3.05 |
ENDS = electronic nicotine delivery systems; Denom = denominator; Num = numerator; wt. = weighted; CI = confidence interval; AOR = adjusted odds ratio; REF = reference.
Statistical adjustments are made for baseline perceptions of addiction, cravings to smoke, cigarettes per day smoked, number of years having smoked, past year quit attempts, use of nicotine replacement theory, poly-use of other combusted tobacco, smoker regret, socio-demographics (age, gender, race/ethnicity, education, household income, MSA status, marital status, sexual orientation, US Census region, children in household), perceived physical health, presence of asthma, chronic bronchitis or COPD, receiving psychological therapy, alcohol consumption, and past year participation in other tobacco studies through GfK.
*Sample sizes for the models may fluctuate due to missing data on importance of ENDS use for quitting smoking, ENDS flavors, and ENDS device type. See S4 Table for results among all baseline smokers based on multiply imputed data.
†Exploratory pairwise comparisons among ENDS exposure groups were conducted. AOR with matching superscripts within an outcome model indicate that these groups were significantly different.