Baseline demographic characteristics of ITC US sample (n=6669)
| Characteristic | n Mean (range) | Per cent |
|---|---|---|
| Sex | ||
| Male | 3032 | (46.5) |
| Female | 3637 | (54.5) |
| Age (yrs) | ||
| 18–24 | 749 | (11.2) |
| 25–44 | 1710 | (25.6) |
| 40–54 | 2436 | (36.5) |
| 55+ | 1774 | (26.6) |
| Race | ||
| Black | 668 | (10.1) |
| Other | 813 | (12.2) |
| White | 5163 | (77.7) |
| Income* | ||
| Low | 2454 | (37.0) |
| Moderate | 2182 | (32.9) |
| High | 1542 | (23.3) |
| No answer | 454 | (6.9) |
| Education† | ||
| Low | 3037 | (45.6) |
| Moderate | 5584 | (38.2) |
| High | 6657 | (16.1) |
| No answer | 12 | (0.2) |
| Number of participants recruited by survey wave | ||
| Wave 1 | 2140 | (32.1) |
| Wave 2 | 684 | (10.3) |
| Wave 3 | 889 | (13.3) |
| Wave 4 | 742 | (11.1) |
| Wave 5 | 745 | (11.1) |
| Wave 6 | 711 | (10.7) |
| Wave 7 | 382 | (5.7) |
| Wave 8 | 376 | (5.6) |
| Number of surveys completed by participants | ||
| 1 | 2969 | 44.5 |
| 2 | 1519 | 22.8 |
| 3 | 876 | 13.1 |
| 4 | 498 | 7.5 |
| 5 | 319 | 4.8 |
| 6 | 212 | 3.2 |
| 7 | 124 | 1.9 |
| 8 | 152 | 2.3 |
*Income defined as low=≤US$29 999; medium=US$30 000–US$59 999; high ≥US$60 000.
†Education defined as low: ≤high school; moderate=some college/tech/trade school; high=college graduate degree or higher.
ITC, International Tobacco Control.