Table 1.
Demographic and smoking characteristics for analytic sample (n = 586)
| Characteristic | Summarya |
|---|---|
| Sex | |
| Female | 340 (58.0%) |
| Male | 243 (42.0%) |
| Race/ethnicity | |
| White | 445 (75.9%) |
| Nonwhite | 141 (24.1%) |
| Age at 8-year follow-up | 24.3 (0.8) |
| Past-month smoking frequency b | |
| 5-year follow-up | 14.5 (12.5) |
| 6-year follow-up | 14.4 (12.9) |
| 7-year follow-up | 13.8 (13.1) |
| 8-year follow-up | 11.2 (13.1) |
| Lifetime e-cigarette use | |
| 5-year follow-up | 217 (37.0%) |
| 6-year follow-up | 273 (47.2%) |
| 7-year follow-up | 350 (60.0%) |
| 8-year follow-up | 353 (60.0%) |
| Past-month e-cigarette frequency b (ever users) | |
| 5-year follow-up | 0.7 (2.0) |
| 6-year follow-up | 1.0 (3.2) |
| 7-year follow-up | 1.9 (4.5) |
| 8-year follow-up | 1.5 (4.6) |
| Nicotine Dependence Syndrome Scale Score | |
| 5-year follow-up | 2.0 (0.9) |
| 6-year follow-up | 2.1 (0.9) |
| 7-year follow-up | 2.1 (0.9) |
| 8-year follow-up | 2.1 (0.9) |
| Used e-cigarettes to quit (ever users) | |
| 5-year follow-up | 62 (28.6%) |
| 6-year follow-up | 101 (37.0%) |
| 7-year follow-up | 148 (42.4%) |
| 8-year follow-up | 166 (50.8%) |
aCategorical variables are summarized as n (valid percentage) and continuous variables are summarized as mean (standard deviation).
bFrequency is in units of number of days of the past 30.