Table 1. Baseline characteristics.
| Baseline characteristics | IPF group (n = 117) | CTD-ILD (n = 19) | Unclassifiable ILD (n = 40) |
|---|---|---|---|
| Treatment time of pirfenidone (weeks) | 52±35 | 50±25 | 41±25 |
| Age (years) | 63.6±8.4 | 61.9±10.9 | 59.4±8.6 |
| Male, n (%) | 110 (94.0) | 8 (42.1) | 21 (52.5) |
| BMI (kg/m2) | 24.4±2.9 | 23.6±2.5 | 23.2±2.3 |
| Time since IPF/ILD diagnosis (years) | 2.6±1.9 | 3.1±2.1 | 2.0±1.1 |
| Surgical lung biopsy (including video-assisted thoracoscopic surgery and cryobiopsy), n (%) | 12 (10.2) | 1 (5.3) | 0 |
| Smoking status, n (%) | |||
| Former smoker | 60 (51.3) | 3 (15.8) | 9 (22.5) |
| Never smoker | 45 (38.5) | 16 (74.2) | 31 (77.5) |
| Active smoker | 12 (10.2) | 0 | 0 |
| Supplemental oxygen, n (%) | 48 (41.0) | 6 (31.6) | 14 (35.0) |
| Comorbidities, n (%) | |||
| CPFE | 20 (17.1) | 1 (5.3) | 1 (2.5) |
| Asthma | 3 (2.6) | 0 | 0 |
| Diabetes mellitus | 18 (15.4) | 5 (26.3) | 1 (2.5) |
| Hypertension | 21 (17.9) | 2 (10.5) | 1 (2.5) |
| Atrial fibrillation | 5 (4.3) | 0 | 1 (2.5) |
| Coronary artery disease | 23 (19.7) | 2 (10.5) | 2 (5.0) |
| Congestive heart failure | 7 (6.0) | 0 | 0 |
| Concurrent medication use, n (%) | |||
| Acid reflux medication | 18 (15.4) | 2 (10.5) | 2 (5.0) |
| Prednisone | 8 (6.8) | 12 (73.2) | 19 (47.5) |
| Cyclophosphamide | 3 (2.6) | 3 (15.8) | 5 (12.5) |
| Azathioprine | 1 (0.9) | 3 (15.8) | 1 (2.5) |
| Methotrexate | 0 | 1 (5.3) | 0 |
| Tacrolimus | 0 | 0 | 2 (5.0) |
Measurement data were presented as mean±standard deviation and enumeration data were reported as a number with percentage. CTD-ILD group included patients with rheumatoid arthritis-ILD (RA-ILD), primary Sjogren's syndrome-ILD (PSS-ILD), systemic sclerosis-ILD (SSc-ILD) and other CTD-ILD. CTD-ILD = connective tissue disease-associated ILD; ILD = interstitial lung disease; IPF = idiopathic pulmonary fibrosis; CPFE = combined pulmonary fibrosis and emphysema; GERD = gastroesophageal reflux disease; SD = standard deviation.