Table 3. DLco decline analysis in different subgroups of IPF patients.
| Cohort | Subgroup | DLco
data available cases/all case |
Relative 1-year DLco
decline (%) |
Absolute 1-year DLco
decline (mls/min/mmHg) |
||
|---|---|---|---|---|---|---|
| Number
of ≥15% (proportion) |
Number of ≥10% (proportion) |
Mean | 95% CI of difference between subgroups |
|||
| Derivation cohort | Non-CPFE | 132/183 | 52 (39.39%) | 73 (55.30%) | 645.39 | -881.03~129.87* |
| CPFE with emphysema <10% | 125/174 | 42 (33.60%) | 60 (48%) | 1020.97 | -752.33~301.34# | |
| CPFE with emphysema ≥10% | 107/143 | 42 (39.25%) | 59 (55.14%) | 870.88 | -683.49~383.31^ | |
| Replication cohort | Non-CPFE | 108/152 | 30 (27.78%) | 43 (39.81%) | 769.10 | -228.07~536.20* |
| CPFE with emphysema <10% | 161/206 | 38 (23.60%) | 67 (41.61%) | 615.04 | -222.08~597.87# | |
| CPFE with emphysema ≥10% | 117/152 | 42 (35.90%) | 64 (54.70%) | 581.21 | -407.07~339.41^ | |
| Combined drug trial cohort | Non-CPFE | 213/236 | 71 (33.33%) | 100 (46.95%) | 748.91 | -450.51~220.82* |
| CPFE with emphysema <10% | 238/261 | 66 (27.73%) | 112 (47.06%) | 863.75 | -448.18~316.55# | |
| CPFE with emphysema ≥10% | 146/157 | 54 (36.99%) | 80 (54.79%) | 814.72 | -423.13~325.08^ | |
The proportions of patients with more than 15% and 10% relative 1-year DLco decline, and the mean of absolute 1-year DLco decline in derivation, replication cohorts and combined drug trial cohort (patients fulfilling criteria to enter IPF therapeutic trials in derivation and replication cohorts) are shown in this table. The number of subjects with available DLco decline versus the number of all subjects belonging to a certain subgroup is shown in n/n format. We also compared a) non-CPFE with CPFE with emphysema <10%, b) non-CPFE with CPFE with emphysema ≥10%, c) CPFE with emphysema ≥10% and CPFE with emphysema <10%, in terms of the relative decline and absolute decline. We use *, # and ^ to denote comparison a), b), c) respectively in the table. None of the comparisons showed statistically significant differences. CPFE: combined pulmonary fibrosis and emphysema; IPF: idiopathic pulmonary fibrosis; DLco: diffusing capacity of the lung for carbon monoxide; CI: confidence interval.