Table 1 Baseline characteristics of non-smokers by cotinine concentrations
| Â | Cotinine (ng/mL) | Â | ||
|---|---|---|---|---|
|  | 0–0.6 | 0.7–2.6 | 2.7–14.9 |  |
|  | N = 2882 | N = 850 | N = 313 | P valuesa |
| Â | N (%) | N (%) | N (%) | Â |
Age (years) | ||||
 45–59 | 1338 (46.4) | 406 (47.8) | 124 (39.6) | 0.042 |
  ≥ 60 | 1544 (53.6) | 444 (52.2) | 189 (60.4) |  |
Sex | ||||
 Male | 1250 (43.4) | 423 (49.8) | 167 (53.4) | < 0.001 |
 Female | 1632 (56.6) | 427 (50.2) | 146 (46.6) |  |
Deprivation quintile | ||||
 1(most deprived) | 315 (10.9) | 137 (16.1) | 75 (24.0) | < 0.001 |
 2 | 479 (16.7) | 190 (22.4) | 82 (26.2) |  |
 3 | 622 (21.6) | 202 (23.8) | 55 (17.6) |  |
 4 | 697 (24.2) | 153 (18.0) | 50 (16.0) |  |
 5(least deprived) | 644 (22.3) | 141 (16.6) | 40 (12.8) |  |
 Missing | 125 | 27 | 11 |  |
Body mass index (kg/m2) | ||||
  < 25.0 | 670 (23.2) | 151 (17.8) | 46 (14.7) | < 0.001 |
 25.0–29.9 | 1181 (41.0) | 347 (40.8) | 122 (39.1) |  |
  ≥ 30 | 757 (26.3) | 272 (32.0) | 122 (39.0) |  |
 Missing | 274 | 80 | 23 |  |
Physically active | ||||
 No | 1441 (50.0) | 450 (52.9) | 177 (56.5) | < 0.001 |
 Yes | 1251 (43.4) | 332 (39.1) | 101 (32.3) |  |
 Missing | 190 | 68 | 35 |  |
Alcohol consumption | ||||
 Never drinker | 237 (8.2) | 51 (6.0) | 25 (8.0) | < 0.001 |
 Ex drinker | 129 (4.5) | 43 (5.1) | 23 (7.3) |  |
 Low-risk drinker | 2300 (79.8) | 655 (77.1) | 211 (67.4) |  |
 Increasing-risk drinker | 163 (5.7) | 66 (7.8) | 33 (10.5) |  |
 High-risk drinker | 51 (1.8) | 34 (4.0) | 19 (6.1) |  |
 Missing | 2 | 1 | 2 |  |
Smoking status | ||||
Never smokers | 1631 (56.6) | 434 (51.1) | 151 (48.2) | < 0.000b |
Ex-smokers stopped smoking ≥5 years | 1149 (39.9) | 341 (40.1) | 130 (41.5) |  |
Ex-smokers stopped smoking ≥1 year | 1225 (42.5) | 398 (46.8) | 151 (48.2) |  |
Ex-smokers stopped smoking < 1 year | 22 (0.8) | 16 (1.9) | 11 (3.5) |  |
Missing | 4 | 2 | 0 | Â |