Table 1.
Cohort PFT Characteristics
| Characteristic | Derivation Cohort |
External Validation Cohort |
Prospective Validation Cohort |
|||
|---|---|---|---|---|---|---|
| ILD Present (n = 212) | ILD Absent (n = 1,059) | ILD Present (n = 68) | ILD Absent (n = 316) | ILD Present (n = 63) | ILD Absent (n = 280) | |
| Age | 67.9 ± 12.1 | 60.5 ± 14.6 | 67.8 ± 11.4 | 62.4 ± 13.2 | 71.4 ± 9.7 | 61.3 ± 14.8 |
| Male sex | 107 (50.5) | 481 (45.4) | 47 (69.1) | 162 (51.3) | 30 (47.6) | 124 (44.3) |
| Reference race | ||||||
| White | 182 (85.9) | 870 (82.2) | 66 (97.1) | 302 (95.6) | 56 (89.9) | 236 (84.3) |
| African American | 21 (9.9) | 101 (9.5) | 2 (2.9) | 6 (1.9) | 3 (4.8) | 26 (9.3) |
| Hispanic | 9 (4.3) | 88 (8.3) | 0 | 8 (2.5) | 4 (6.3) | 18 (6.4) |
| BMI, kg/m2 | 28.6 ± 6.2 | 29.6 ± 7.3 | 29.2 ± 5.2 | 28 ± 6.4 | 30.4 ± 6.7 | 30.1 ± 7.7 |
| Height, cm | 167.5 ± 9.8 | 167.9 ± 10 | 164.5 ± 8.7 | 164.5 ± 9.1 | 166.6 ± 8.6 | 168 ± 10.3 |
| Weight, kg | 78.6 ± 19.2 | 81.9 ± 22.6 | 77.6 ± 15.2 | 74.2 ± 18.6 | 82.4 ± 21 | 83.8 ± 24 |
| TLC, L | 4.3 ± 1.3 | 5.4 ± 1.5 | 4.5 ± 1.3 | 5.5 ± 1.4 | 4.9 ± 1.3 | 5.4 ± 1.5 |
| TLC (% predicted) | 73.8 ± 19.2 | 93.4 ± 18 | 76.9 ± 18.6 | 97.5 ± 18 | 85.8 ± 16.2 | 91.1 ± 15.4 |
| TLC < 80% predicted | 130 (61.3 | 238 (22.5) | 40 (58.8) | 43 (13.6) | 20 (31.8) | 71 (25.4) |
| FEV1, L | 1.9 ± 0.7 | 2.2 ± 0.9 | 2.2 ± 0.7 | 2.2 ± 0.8 | 2 ± 0.6 | 2.2 ± 0.8 |
| FEV1 (% predicted) | 74.2 ± 22 | 75.4 ± 22.3 | 85.3 ± 21.6 | 80.5 ± 23.2 | 81.6 ± 18.8 | 78.3 ± 20.1 |
| FEV1 < 80% predicted | 127 ± 59.9 | 571 ± 53.9 | 26 ± 38.2 | 131 ± 41.5 | 28 ± 44.4 | 147 ± 52.5 |
| FVC, L | 2.6 ± 0.9 | 3.2 ± 1.1 | 2.7 ± 0.9 | 3.1 ± 1 | 2.9 ± 0.9 | 3.2 ± 1 |
| FVC (% predicted) | 75.2 ± 22.1 | 85.8 ± 20 | 77.7 ± 20.2 | 87.2 ± 19.5 | 95.9 ± 27.1 | 87.2 ± 19.5 |
| FVC < 80% predicted | 117 (55.2) | 359 (33.9) | 43 (63.2) | 97 (30.7) | 20 (31.8) | 66 (23.6) |
| FEV1/FVC | 0.75 ± 0.1 | 0.68 ± 0.1 | 0.82 ± 0.1 | 0.7 ± 0.1 | 0.72 ± 0.1 | 0.7 ± 0.1 |
| FEV1/FVC > 0.8 | 76 (35.9) | 175 (16.5) | 42 (61.7) | 86 (27.2) | 15 (23.8) | 40 (14.3) |
| Dlco, mL/mm Hg/min | 11.7 ± 4.4 | 17.3 ± 6 | 13.5 ± 5.2 | 16.9 ± 5.9 | 14.1 ± 4.9 | 18 ± 5.6 |
| Dlco (% predicted) | 49.5 ± 17.4 | 68.9 ± 18.3 | 58 ± 20 | 70.8 ± 19 | 61.4 ± 17.2 | 71.6 ± 15.8 |
| Dlco < 80% predicted | 201 (94.8) | 769 (72.6) | 57 (83.8) | 217 (68.7) | 55 (87.3) | 198 (70.7) |
| PFT indication | ||||||
| Pulmonary disease/symptom | 178 (84) | 679 (64.1) | 57 (83.8) | 192 (60.8) | 50 (79.4) | 168 (60) |
| Nonpulmonary disease/symptom | 34 (16) | 380 (35.9) | 11 (16.2) | 124 (39.2) | 13 (20.6) | 112 (40) |
Values are expressed as mean ± SD or No. (%). Dlco = diffusing capacity of the lung for carbon monoxide; ILD = interstitial lung disease; PFT = pulmonary function test; TLC = total lung capacity.