Clinical features of sample (n=114)
| Smoking status | |
| Current | 58 (51%) |
| Never | 22 |
| Ex-smoker for > 10 years | 17 (15%) |
| Asbestos exposure | 16 (14%) |
| Previous malignancy | |
| Colon/rectum | 4 |
| Breast | 3 |
| Skin | 5 |
| Renal | 2 |
| Bladder | 5 |
| Other | 11 |
| Total | 27 (24%) |
| Two or more malignancies | 4 (3.5%) |
| Exercise tolerance | |
| Unlimited, normal | 80 (70%) |
| Limited by dyspnoea | 24 (21%) |
| Limited by other factors | 6 (5%) |
| No data 4 (3.5%) | |
| Lung function (litres) | |
| FEV1 < 1.0 | 5 (4%) |
| FEV1 >1 and < 1.5 | 15 (13%) |
| FEV1 >1.5 and > 2.0 | 43 (38%) |
| FEV1 >2.0 | 51 (45%) |