Sample demographic and intervention characteristics (N=18 080)
| Characteristics | N | % |
|---|---|---|
| Mean age (±SD)* | 34.8 (±11.5) | |
| Median age (IQR)* | 32 (24–43) | |
| Gender | ||
| Female | 11 304 | 62.5 |
| Male | 6570 | 36.3 |
| Missing | 206 | 1.1 |
| Baseline smoking frequency | ||
| Daily smoker | 15 918 | 88.0 |
| Non-daily smoker | 1395 | 7.8 |
| Missing | 767 | 4.2 |
| Web-enabled phone | ||
| No | 1058 | 5.9 |
| Yes | 12 572 | 69.5 |
| Missing | 4450 | 24.6 |
| Region | ||
| Midwest | 3081 | 17.0 |
| Northeast | 2589 | 14.3 |
| South | 5810 | 32.1 |
| West | 3377 | 18.7 |
| Missing | 3223 | 17.8 |
| Treatment completion | ||
| Treatment completed | 9686 | 53.6 |
| Opted out before treatment completed | 8394 | 46.4 |
*N for age is 17 577 due to missing values and exclusion of ages above 99 and below 0.