Table 3.

Geometric means and geometric mean ratios of children's hair nicotine concentration by age and total time spent at home

Hair nicotine (ng/mg), GM (95% CI)PGMR (95% CI)
Per 1 μg/m3 increase in air nicotine at home
    Children ≥6 y, who spent <19 h/d (n = 311)1.01 (1.00, 1.03)0.00141.00 (Reference)
    Children <6 y, who spent <19 h/d (n = 135)1.14 (1.06, 1.23)<0.0011.12 (1.05, 1.20)
    Children ≥6 y, who spent ≥19 h/d (n = 151)1.16 (1.09, 1.24)<0.0011.15 (1.07, 1.23)
    Children <6 y, who spent ≥19 h/d (n = 309)1.31 (1.20, 1.42)<0.0011.29 (1.12, 1.48)
At centered median SHS exposure level of 0.16 μg/m3
    Children ≥6 y, who spent <19 h/d at home0.46 (0.32, 0.68)<0.0011.00 (Reference)
    Children <6 y, who spent <19 h/d at home0.68 (0.46, 1.02)0.071.47 (1.19, 1.82)
    Children ≥6 y, who spent ≥19 h/d at home0.53 (0.35, 0.79)0.0081.14 (0.90, 1.43)
    Children <6 y, who spent ≥19 h/d at home0.78 (0.53, 1.13)0.271.67 (1.15, 2.06)