Table 2– Summary of characteristics for the lung cancer, chronic obstructive pulmonary disease (COPD) and control smokers
ParameterLung cancerCOPDControl smokers
Subjects n454458488
Males %535960
Age yrs69±1066±965±10
Height* m1.67±0.081.68±0.091.69±0.09
Smoking history
 Current smoking %354048
 Age started yrs18±417±317±3
 Smoking exposure yrs41±1242±1135±11
 Smoking exposure* pack-yrs41±2547±2040±19
 Smoking exposure cigarettes·day−120±1023±924±11
Time since smoking cessation yrs11.4±6.79.8±7.413.9±8.1
History of other exposures %
 Work dust exposure*635947
 Work fume exposure414038
 Asbestos exposure*232216
Family history %
 COPD333728
 Lung cancer*19119
Lung function
 FEV1* L1.86±0.481.25±0.482.86±0.68
 FEV1* % pred734699
 FEV1/FVC* %64±1346±878±7
 Spirometric COPD#,* %511000
  • Data are presented as mean±sd, unless otherwise stated. FEV1: forced expiratory volume in 1 s; % pred: % predicted; FVC: forced vital capacity. #: according to Global Initiative for Chronic Obstructive Lung Disease criteria, stage II or higher; : no significant difference after log transformation due to skewed distribution. *: p<0.05.