Unadjusted odds ratio (CL) | p-value | Adjusted odds ratio# (CL) | p-value | |
Others actively smoke in the home | 6.7 (2.2–20.7) | 0.001 | 10.8 (2.3–49.9) | 0.002 |
Chronic phlegm production | 3.2 (1.6–6.5) | 0.001 | 3.5 (1.6–7.7) | 0.002 |
Number of pack-yrs | 1.0 (0.98–1.0) | 0.9 | 1.0 (0.98–1.0) | 0.9 |
FEV1 post-BD % pred¶ | 1.0 (0.98–1.1) | 0.4 | 1.0 (0.97–1.1) | 0.5 |
CL: confidence limits; FEV1: forced expiratory volume in one second; post-BD: after bronchodilator administration; % pred: % predicted. #: the full model includes all four variables; ¶: post-BD spirometry was unavailable for 11 probands. The pre-bronchodilator FEV1 was also not statistically significant in a separate model.