Table 3.
Linear regression models of predicted BC (average summer and winter) by lung function measures, stratified by smoking status (n = 272): effect estimate [% (95% CI)] for change in percent predicted lung function per IQR increase in BC (0.22 μg/m3).
| BC model | FEV1 | FVC | FEF25–75% |
|---|---|---|---|
| Current smokers (n = 48) | 0.62 (−2.1 to 3.4) | 0.64 (−2.0 to 3.3) | 2.63 (−3.7 to 8.9) |
| Former smokers (n = 61) | −4.40 (−7.8 to −1.0) | −3.11 (−6.1 to −0.2) | −8.78 (−14.7 to −2.9) |
| Nonsmokers (n = 163) | −0.98 (−2.9 to 0.9) | −0.32 (−2.0 to 1.4) | −4.39 (−8.1 to −0.6) |
a
We adjusted all models for age, race/ethnicity, education level, asthma/chronic bronchitis diagnosis, and year of assessment.