| Characteristics | Non-RD | AE | p-value | Infection# | p-value¶ |
| Patients | 298 | 90 | 37 | ||
| Age yrs | 63.4±8.1 | 64.3±8.9 | ns | 63.7±8.6 | ns |
| Males | 228 (76.5) | 69 (76.7) | ns | 30 (81.1) | ns |
| Smoking | 0.107 | ns | |||
| Never smoked | 76 (25.5) | 31 (34.4) | 10 (27.0) | ||
| Smokers | 222 (74.5) | 59 (65.6) | 27 (73.0) | ||
| Smoking exposure pack-yrs | 34.8±19.2 | 35.7±20.0 | ns | 34.0±16.2 | ns |
| PFT % pred+ | |||||
| FVC | 77.6±17.0 | 72.0±15.7 | 0.005 | 75.5±18.5 | ns |
| DL,CO | 66.4±19.0 | 62.2±19.3 | ns | 61.2±18.0 | 0.088 |
| TLC | 78.7±14.4 | 73.8±15.0 | 0.021 | 75.9±18.5 | ns |
| FEV1 | 88.5±18.0 | 86.0±18.3 | ns | 89.0±17.5 | ns |
| BAL %+ | |||||
| Macrophages | 71.0±18.4 | 67.8±16.4 | ns | 66.9±16.1 | ns |
| Lymphocytes | 15.7±12.4 | 15.7±11.2 | ns | 18.2±14.2 | ns |
| Neutrophils | 9.4±14.1 | 11.3±13.7 | ns | 10.8±9.4 | ns |
| Eosinophils | 3.2±4.6 | 3.2±4.4 | ns | 1.9±2.3 | ns |
| CRP mg·dL−1+ | 0.5±0.7 | 0.4±0.3 | ns | 0.7±0.7 | 0.055 |
| Steroid with/without cytotoxic agent§ | 184 (61.7) | 56 (62.2) | ns | 20 (54.1) | ns |
Data are presented as n, mean±sd or n (%), unless otherwise stated. RD: rapid deterioration; PFT: pulmonary function test; % pred: % predicted; FVC: forced vital capacity; DL,CO: diffusing capacity of the lung for carbon monoxide; TLC: total lung capacity; FEV1: forced expiratory volume in 1 s; BAL: bronchoalveolar lavage; CRP: C-reactive protein; ns: nonsignificant. #: infection with bilateral lesions; ¶: No-RD versus infection; +: data from the patients who first presented with RD were excluded; §: within 30 days prior to RD.