| Variable | Bronchodilator response group | ||
| A | B | C | |
| No of patients at baseline | 33 | 38 | 22 |
| FEV1 % predicted | 59.09 (4.03) | 58.38 (3.03) | 74.65 (4.29)*† |
| FEV1 : FVC | 0.47 (0.02) | 0.45 (0.02) | 0.51 (0.02) |
| KCO % predicted | 90.24 (5.19) | 90.42 (5.21) | 94.86 (6.79) |
| Visible emphysema (at baseline) | 44.6% | 65.1% | 50% |
| UZVI | 26.91 (3.08) | 28.32 (2.83) | 28.00 (2.94) |
| LZVI | 25.51 (3.02) | 27.83 (2.24) | 28.96 (3.00) |
| Change in FEV1 (ml/year) | −29.88 (16.28) | −25.26 (9.42) | −67.35 (19.18)† |
| Change in FEV1 (% predicted/year) | −0.705 (0.808) | −0.604 (0.396) | −1.989 (0.928) |
| Change in FEV1 : FVC (%/year) | −4.01 (4.99) | −2.32 (2.27) | −5.10 (3.05) |
| Change in KCO (% predicted/year) | −2.75 (0.83)† | −0.77 (0.59)* | −0.02 (0.61)* |
| Change in UZVI (%/year) | +1.23 (0.74) | +0.37 (0.47) | −0.28 (0.59) |
| Change in LZVI (%/year) | +1.16 (0.47) | +0.52 (0.43) | −0.62 (0.89)* |
Post-bronchodilator lung function values and voxel indices are from baseline and expressed as mean (standard error). *Significant difference (p<0.05) from group A; †Significant difference (p<0.05) from group B; LZVI, lower zone voxel index (−910 Hounsfield units); UZVI, upper zone voxel index (−910 Hounsfield units).