| Variable | Survivors | Nonsurvivors | p-value |
| Subjects n | 37 | 33 | |
| Age yrs | 66±4 | 67±9 | ns |
| BMI m·kg−2 | 29±4 | 27±3 | 0.0384 |
| Time to diagnosis months | 20±19 | 27±22 | ns |
| Smoking pack-yrs | 32±16 | 34±22 | ns |
| Concomitant emphysema yes/no (%) | 9/28 (24) | 15/18 (45) | 0.0267 |
| MRC dyspnoea score | 2.1±0.8 | 3.3±1.1 | <0.0001 |
| 6MWD m | 412±128 | 319±153 | 0.0184 |
| 6MWD % pred | 89±27 | 66±27 | 0.0018 |
| Desaturation at 6MWT# yes/no (%) | 19/16 (54) | 25/4 (86) | 0.0061 |
| PA–a,O2 mmHg | 28±13 | 36±17 | 0.0392 |
| FVC % pred | 81±21 | 68±23 | 0.0027 |
| DL,CO % pred | 53±17 | 37±17 | 0.0005 |
| CPI | 43±15 | 55±13 | 0.0006 |
| HRCT disease extent % of total lung volume | 33±11 | 41±11 | 0.0098 |
| BAL total cell count cells·mL−1 | 417972±319004 | 952444±623505 | 0.0037 |
Data are presented as mean±sd, unless otherwise stated. BMI: body mass index; MRC: Medical Research Council; 6MWD: 6-min walking distance; % pred: % predicted; 6MWT: 6-min walking test; PA–a,O2: alveolar–arterial oxygen tension difference; FVC: forced vital capacity; DL,CO: diffusing capacity of the lung for carbon monoxide; CPI: composite physiologic index; HRCT: high-resolution computed tomography; BAL: bronchoalveolar lavage; ns: not significant. p-value: Chi-squared, unpaired t-test or Mann–Whitney U-test, where required. #: arterial oxygen saturation ≤88%.