Characteristics of the high and low lung function groups
| High group (n=537) | Low group (n=533) | p value | |
|---|---|---|---|
| Values for continuous variables are mean (SE). | |||
| *Number of packs of cigarettes smoked per day×number of years smoking. | |||
| †Lung function at the start of the study. | |||
| ‡Change in lung function per year over a 5 year period measured as % predicted FEV1. | |||
| §Percentage change in FEV1 from baseline in response to a bronchodilator. | |||
| FEV1=forced expiratory volume in 1 second. | |||
| F/M | 183/354 | 203/330 | 0.17 |
| Age (years) | 46.2 (0.3) | 50.7 (0.3) | <0.0001 |
| Smoking history (pack years)* | 35.3 (0.8) | 45.1 (0.8) | <0.0001 |
| Baseline FEV1 (% predicted† | 91.8 (0.1) | 62.6 (0.1) | – |
| Rate of decline in lung function‡ | −0.6 (0.1) | −1.2 (0.1) | <0.0001 |
| Bronchodilator response (%)§ | 6.2 (0.2) | 2.7 (0.3) | <0.0001 |