Baseline age, smoking characteristics, and differences in spirometric results between continuing smokers and quitters
| Variable | Smokers(n = 2391) | Quitters(n = 686) | p value |
|---|---|---|---|
| Values are mean (SD) unless otherwise indicated. | |||
| FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; FTND, Fagerström test for nicotine dependence. | |||
| Age (years) | 51.8 (10.1) | 53.2 (11.7) | <0.005 |
| Age at smoking initiation (years) | 19.6 (4.7) | 20.3 (5.4) | <0.005 |
| Cigarettes per day | 19.5 (8.2) | 16.9 (8.3) | <0.001 |
| Pack-years | 30.7 (16.6) | 27.4 (18.1) | <0.001 |
| FEV1/FVC (%) | 74.7 (12.6) | 72.3 (13.7) | <0.001 |
| FEV1 (l) | 2.73 (0.9) | 2.62 (1.1) | <0.02 |
| Airway obstruction, n (%) | 753 (31.5%) | 273 (39.8%) | <0.001 |
| FTND (points) | 4.98 (2.4) | 4.04 (2.4) | <0.001 |
| No. of previous cessations | 1.60 (3.5) | 1.96 (3.6) | 0.055 |