| Parameter | CT group | Control group | ||||
| Continuous ex-smokers(n = 422) | Re-starters(n = 47) | p Value | Continuous ex-smokers(n = 375) | Re-starters(n = 44) | p Value | |
| Years of smoking abstinence | 3.7 (3.0) | 1.0 (1.4) | <0.01 | 3.8 (2.9) | 1.0 (1.4) | <0.01 |
| FEV1/FVC | 71.5 (7.4) | 70.9 (8.4) | 0.57 | 72.3 (7.5) | 71.2 (8.9) | 0.34 |
| Age at onset of smoking (years) | 16.7 (3.3) | 16.5 (3.9) | 0.72 | 16.7 (3.2) | 16.5 (2.7) | 0.73 |
| Pack-years | 35.7 (13.2) | 40.4 (17,8) | 0.03 | 36.0 (14.9) | 36.6 (13.6) | 0.80 |
Values are mean (SD) baseline values.
FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.