Lung function* | Study entry(N = 2057) | 1-year lag(N = 1882) | 2-year lag(N = 1673) |
HR (95% CI)† | HR (95% CI)† | HR (95% CI)† | |
FVC (%) | 0.94 (0.68 to 1.32) | 0.66 (0.47 to 0.94)‡ | 0.71 (0.48 to 1.05)¶ |
FEV1 (%) | 0.68 (0.48 to 0.95)‡ | 0.50 (0.37 to 0.68)§ | 0.57 (0.39 to 0.82)§ |
FEF25–75 (%) | 0.50 (0.35 to 0.71)§ | 0.38 (0.26 to 0.55)§ | 0.49 (0.32 to 0.76)§ |
FVC, forced vital capacity; FEV1, forced expiratory volume in 1 s; FEF25–75, forced expiratory flow over the mid-range of expiration.
*The percentage predicted lung function measures are scaled to 10th–90th percentile values as follows: 25.3% for FVC, 26.2% for FEV and 57.1% for FEF25–75.
†Hazard ratio and 95% confidence interval.
‡p<0.05; §p<0.005, ¶p<0.10.