Table 3.
Cotinine levels (ng/mL) in children's urine and maternal self-reported smoking habit at 4 years
| Maternal self-reported smoking habit at 4 years | Urinary cotinine in children at 4 years (ng/mL) | |||
| N | Median | Adjusted GM | CI 95% | |
| NENS | 102 | 4.65 | 4.53 | (3.71–5.48) |
| ENS | 62 | 6.45 | 7.10* | (5.61–8.99) |
| DEN child (Tertiles) | ||||
| ≤ 2 | 39 (62.9%) | 5.40 | 6.38 | (4.98–8.18) |
| 2–4 | 15 (24.2%) | 6.50 | 7.23 | (4.83–10.81) |
| >4 | 8 (12.9%) | 10.80 | 11.38 | (6.55–19.77) |
| S | 142 | 19.15 | 19.68* | (16.83–23.01) |
| NDI mother (Tertiles) | ||||
| ≤ 3.6 | 15 (10.6%) | 9.90 | 9.75 | (6.14–15.49) |
| 3.6–9 | 48 (33.8%) | 13.45 | 12.45 | (9.59–16.14) |
| >9 | 79 (55.6%) | 28.50 | 30.41*** | (24.89–37.24) |
* p-value < 0.05 in relation to NENS
*** p-value < 0.001 in relation to the first tertile of maternal NDI
GM: geometric mean; CI: confidence interval; NENS: non exposed-non smoker; ENS: exposed-non smoker; S: smoker; NDI:nicotine daily intake; DEN: daily exposure to nicotine.