Lung function with exposure to environmental tobacco smoke measured from a combination of questionnaire and serum cotinine
Self reported environmental tobacco smoke and serum cotinine | Residual | Case-control | |||||
---|---|---|---|---|---|---|---|
Mean | 95% CI | OR4-150 | 95% CI | OR4-151 | 95% CI | ||
FEV1: | |||||||
Low exposure4-152 | 0.158 | 2.238 to 0.293 | 1.00 | 1.00 | |||
Middle exposure4-152 | −0.018 | −0.859 to 0.050 | 2.88 | 1.42 to 5.84 | 2.91 | 1.43 to 5.91 | |
High exposure4-152 | −0.032 | −0.126 to 0.062 | 3.12 | 1.39 to 6.99 | 3.15 | 1.40 to 7.07 | |
FVC: | |||||||
Low exposure4-152 | 0.196 | 0.031 to 0.360 | 1.00 | 1.00 | |||
Middle exposure4-152 | −0.005 | −0.093 to 0.082 | 2.08 | 1.02 to 4.21 | 2.01 | 0.99 to 4.09 | |
High exposure4-152 | −0.070 | −0.187 to 0.047 | 2.56 | 1.15 to 5.72 | 2.49 | 1.11 to 5.58 |
↵4-150 OR adjusted for sex, deprivation score, and total energy intake.
↵4-151 OR further adjusted for respiratory symptoms.
↵4-152 The 1st, 2nd and 3rd tertile values for cotinine concentrations (ng/ml) were 0, 0.01–1.02 and 1.03–17.49; for exposure hours a day they were <1, 1–2 and >2; and for total environmental tobacco smoke scores they were 3–4, 5–6 and 7–12. They were scored at 1, 2, and 3 respectively. Those with scores 3–4 were defined as low exposure to environmental tobacco smoke (n=48), scores 5–7 as middle exposure (n=160), and scores 8–9 as high exposure (n=70).