Annual rate of disease progression related to disease severity: data expressed as median (IQR)
| Group 1 | Group 2 | Group 3 | Group 4 | JT test (p value) | |
|---|---|---|---|---|---|
| The number in each subgroup is as shown in table 2. | |||||
| Group 1: FEV1 >80% predicted; Group 2: FEV1 50–79% predicted; Group 3: FEV1 30–49% predicted; Group 4: FEV1 <30% predicted. | |||||
| FEV1, forced expiratory volume in 1 second; VI −950, voxel index at a threshold of −950 HU; Perc15, 15th percentile point; UZ, upper zone scans; LZ, lower zone scans; Rate = annual progression rate over 2 years; Combined = average of upper and lower zone scans; JT, Jonckheere-Terpstra test. | |||||
| FEV1 rate (ml) | −83.0 (−190.8 to −32.8) | −108.9 (−234.4 to −73.5) | −54.8 (−82.4 to −17.8) | −30.6 (−45.9 to 4.9) | 3.56 (p<0.001) |
| UZ Perc15 rate (HU) | 0.8 (−4.9 to 3.3) | −3.8 (−4.7 to −1.4) | −2.9 (−4.9 to 0.1) | −3.1 (−4.5 to −0.1) | −0.5 (p = 0.65) |
| LZ Perc15 rate (HU) | −2.1 (−5.6 to 1.5) | −1.9 (−2.8 to 1.4) | −2.4 (−4.1 to −0.2) | −0.9 −3.6 to 1.4) | 0.29 (p = 0.76) |
| Combined Perc15 rate (HU) | −1.2 (−4.5 to 2.8) | −2.5 (−4.1 to −0.2) | −1.9 (−4.2 to −0.5) | −1.9 (−4.7 to 0.8) | −0.5 (p = 0.595) |
| UZ VI −950 rate (%) | −0.1 (−0.5 to 0.9) | 1.4 (0.5 to 2.4) | 1.2 (0.2 to 2.4) | 2.3 (−0.1 to 3.5) | 2.85 (p = 0.004) |
| LZ VI −950 rate (%) | 0.2 (−0.5 to 0.8) | 0.6 (−1.8 to 1.8) | 1.3 (0.1 to 3.6) | 2.2 (−0.7 to 3.4) | 2.56 (p = 0.018) |
| Combined VI −950 rate (%) | 0.1 (−0.4 to 0.7) | 1.1 (−0.3 to 1.9) | 1.3 (0.5 to 2.7) | 2.0 (0.1 to 3.9) | 2.87 (p = 0.004) |