Lung function
| All (382) | Belfast (95) | Brompton (99) | Leicester (79) | Manchester (109) | ||
| Prebronchodilator spirometry (n) FEV1 (litres) % predicted | (371) | (95) | (96) | (77) | (103) | |
| 1.94±0.81 | 1.92±0.70 | 1.86±0.078 | 2.21±0.86 | 1.84±0.87 | p=0.013 | |
| 65.9±23.6 | 65.7±24.0 | 60.4±20.4 | 75.3±22.8 | 64.7±25.0 | p=0.001 | |
| FVC (litres) % predicted | 3.07±1.01 | 3.07±0.87 | 3.26±1.07 | 3.11±1.10 | 2.90±1.00 | p=0.081 |
| 81.9±19.8 | 82.5±20.2 | 82.4±20.4 | 83.1±21.1 | 79.1±19.6 | p=0.424 | |
| FEV1/FVC ratio % | 63.1±15.2 | 62.7±14.8 | 56.2±14.5 | 71.1±13.3 | 63.4±14.8 | p<0.001 |
| Subjects with baseline postbronchodilator study (n) | (261) | (62) | (43) | (75) | (81) | |
| Prebronchodilator FEV1 (litres) (% predicted) | 1.90±0.83 | 1.69±0.63 | 1.83±0.80 | 2.22±0.87 | 1.81±0.87 | p=0.001 |
| (64.0±23.1) | (56.9±18.6) | (58.6±20.5) | (75.4±23.0) | (62.7±24.3) | p<0.001 | |
| Prebronchodilator FVC (litres) (% predicted) | 3.05±1.05 | 2.99±0.94 | 3.36±1.15 | 3.11±1.10 | 2.89±1.02 | p=0.128 |
| p=0.220 | ||||||
| (80.6±19.8) | (79.0±19.3) | (84.1±18.1) | (83.3±21.4) | (77.8±19.3) | ||
| Postbronchodilator FEV1 (litres) (% predicted) | p=0.020 | |||||
| 2.18±0.88 | 1.93±0.70 | 2.29±1.03 | 2.36±0.86 | 2.14±0.89 | p=0.004 | |
| (73.6±24.2) | (65.3±21.4) | (73.6±26.3) | (80.7±22.5) | (74.2±24.7) | ||
| Postbronchodilator FVC (litres) (% predicted) | p=0.246 | |||||
| 3.29±1.06 | 3.21±0.97 | 3.60±1.26 | 3.30±1.11 | 3.23±0.95 | p=0.664 | |
| (87.4±19.1) | (85.2±19.9) | (90.9±21.1) | (87.8±20.3) | (87.4±16.4) | ||
| Postbronchodilator FEV1/FVC ratio (%) | p<0.001 | |||||
| 65.0±14.6 | 60.6±12.4 | 61.44±15.82 | 71.6±12.3 | 65.0±15.6 | ||
| Total lung capacity % predicted (n) | 104.9±16.8 (265) | 107.8±17.8 (80) | 109.1±13.9 (96) | 98.0±16.6 (89) | p<0.001 | |
| Residual volume % predicted (n) | 134.4±42.0 (263) | 127.8±44.2 (80) | 151.0±40.1 (97) | 121.8±35.9 (86) | p<0.001 | |
| KCO % predicted (n) | 101.5±17.5 (256) | 97.3±17.7 (79) | 98.0±13.8 (94) | 110.04±18.5 (83) | p<0.001 |
Group data (mean±SD) for all subjects are presented in column 2 followed by data for individual centres. Between-centre comparisons for continuous variables were made using one-way analysis of variance (for posthoc comparisons, see text).
Significance was taken as p<0.01.
FEV1, forced expiratory volume in 1 s. FVC, forced vital capacity, KCO, carbon monoxide transfer coefficient.