Age yrs | 50.34±0.54 |
Male | 252 (58.9) |
Pack-yrs smoked | 15.91±0.71 |
FEV1 % pred | 53.80±1.59 |
K CO % pred | 69.70±1.01 |
Chronic bronchitis | 146 (34.1) |
Data are expressed as frequency (%) or mean±sem. FEV1: forced expiratory volume in 1 s; % pred: % predicted; KCO: transfer coefficient of the lung for carbon monoxide.