Measurement | 2007(n = 1447) | 2008(n = 1461) | p-value |
---|---|---|---|
Median cotinine concentration | 0.10 | 0.10 | - |
Percentage below level of detection (0.1 ng/ml) | 43.98 | 49.90 | - |
Percentage above cotinine concentration (ng/ml) | Â | Â | Â |
0.1* | 56.04 | 50.10 | - |
0.2 | 40.15 | 39.22 | - |
0.5 | 31.44 | 28.82 | - |
1 | 22.88 | 20.33 | - |
1.7 | 14.38 | 13.48 | - |
2 | 12.30 | 10.95 | - |
3 | 7.41 | 5.57 | - |
Unadjusted geometric mean (95% CI) cotinine concentration (ng/ml)** | 0.17 (0.14 to 0.20) | 0.15 (0.13 to 0.18) | 0.10 |
Geometric mean (95% CI) cotinine concentration (ng/ml) adjusted for age, family affluence and time of day data collected** | 0.17 (0.15 to 0.20) | 0.15 (0.13 to 0.17) | 0.07 |