Patient characteristics (n=105)
| Patient characteristic | Distribution (n (%)) |
| Gender | |
| Male | 73 (70) |
| Female | 32 (30) |
| Age | |
| ≤60 years | 49 (47) |
| >60 years | 56 (53) |
| Race | |
| Black | 3 (3) |
| Caucasian | 102 (97) |
| Smoking history | |
| Current smoker | 36 (34) |
| Former smoker | 66 (63) |
| Never smoked | 3 (3) |
| Pack-years | |
| ≤45 | 51 (49) |
| >45 | 50 (48) |
| Unknown | 4 (4) |
| COPD | |
| Yes | 79 (75) |
| No | 19 (18) |
| Unknown | 8 (7) |
| Asbestos | |
| Yes | 50 (48) |
| No | 37 (35) |
| Unknown | 18 (17) |
COPD, chronic obstructive pulmonary disease.