Baseline and clinical characteristics
| Male | 165 (88.7) |
| Age years | 56.10±10.63 |
| Smoking | |
| Current smoker | 118 (63.4) |
| Former smoker | 27 (14.5) |
| Never-smoker | 37 (19.9) |
| Unknown | 4 (2.2) |
| Duration of smoking pack-years | 32.60±17.45 |
| Symptoms# | |
| None | 160 (86.0) |
| Sputum | 12 (6.5) |
| Cough | 5 (2.7) |
| Dyspnoea | 4 (2.2) |
| Chest soreness | 2 (1.1) |
| Throat pain | 1 (0.5) |
| Palpitation | 1 (0.5) |
Data are presented as n (%) or mean±sd. #: multiple symptoms possible.