Table 5

 Directly measured SHS exposure and asthma health status

Exposure measurementSeverity of asthma score Mean difference* (95% CI)Asthma-specific quality of life score Mean difference* (95% CI)Physical health status score Mean difference* (95% CI)
*Multivariate linear regression controlling for age, sex, race, education, marital status, and smoking.
†First 1 cm of hair corresponds approximately to exposure during the previous 1 month; 2–3 cm of hair corresponds approximately to exposure during the previous 2–3 months.
‡p value for linear trend <0.05.
Subject numbers for each tertile/nicotine badge, n = 63 per tertile; hair nicotine, 1 month n = 55, 38, and 45; hair nicotine, 2–3 months n = 40, 42, and 42; hair cotinine, 1 month n = 54, 42, and 42; hair cotinine, 2–3 months, n = 42, 41, and 41.
Higher severity of asthma scores indicate greater asthma severity; higher asthma-specific quality of life scores indicate poorer quality of life; higher SF-12 physical health status scores indicate better health status.
Nicotine badge (previous week)
    First tertile (0–0.03 μg/m3)ReferentReferentReferent
    Second tertile (0.04–0.13 μg/m3)0.32 (−1.03 to 1.66)−0.20 (−4.62 to 4.22)0.91 (−2.64 to 4.47)
    Third tertile (0.14–9.82 μg/m3) 1.56 (0.18 to 2.95)‡ 2.63 (−1.92 to 7.18)−2.34 (−6.00 to 1.32)
Hair nicotine (previous month†)
    First tertile (0 ng/mg))ReferentReferentReferent
    Second tertile (0.01–0.12 ng/mg)0.56 (−1.18 to 2.29)−0.77 (−5.81 to 4.27)2.05 (−2.32 to 6.41)
    Third tertile (0.13–3.15 ng/mg)0.63 (−1.09 to 2.34)−0.26 (−5.24 to 4.71)−1.20 (−5.52 to 3.11)
Hair nicotine (previous 2–3 months†)
    First tertile (0–0.02 ng/mg)ReferentReferentReferent
    Second tertile (0.03–0.19 ng/mg)−0.08 (−1.83 to 1.67)−0.17 (−5.73 to 5.39)−0.22 (−4.85 to 4.41)
    Third tertile (0.20–4.0 ng/mg)1.67 (−0.10 to 3.44)‡1.17 (−4.46 to 6.80)−3.57 (−8.26 to 1.11)
Hair cotinine (previous month†)
    First tertile (0–0.02 ng/mg)ReferentReferentReferent
    Second tertile (0.03–0.10 ng/ml) 1.79 (0.16 to 3.42) 2.15 (−2.64 to 6.95)−1.96 (−6.15 to 2.22)
    Third tertile (0.11–0.78 ng/ml)0.67 (−1.03 to 2.38)0.73 (−4.29 to 5.75)−2.38 (−6.75 to 2.22)
Hair cotinine (previous 2–3 months†)
    First tertile (0–0.03 ng/ml)ReferentReferentReferent
    Second tertile (0.04–0.10 ng/ml)1.11 (−0.61 to 2.84)3.32 (−2.06 to 8.70)−3.07 (−7.79 to 1.65)
    Third tertile (0.11–1.11 ng/ml)1.04 (−0.76 to 2.85)2.45 (−3.07 to 8.08)−3.74 (−8.71 to 1.23)