Table 1

Baseline characteristics of all patients in the internal cohort separated by randomly generated derivation and validation sets

All patientsDerivation setValidation set
N=562N=281N=281
Age (years)72 (66, 77)72 (66, 77)71 (66, 76)
Gender, women129 (23.0)80 (28.5)49 (17.4)
Race, non-white126 (22.4)67 (23.8)59 (21.0)
Body mass index (kg/m2)29.0±6.329.3±6.728.7±5.8
Comorbid disease
 Smoking status ever368 (65.5)179 (63.7)189 (67.3)
 Diabetes mellitus115 (20.5)58 (20.6)57 (20.3)
 Hypertension264 (47.0)121 (43.1)143 (50.9)
 Cardiovascular disease178 (31.7)88 (31.3)90 (32.0)
 Severe OSA128 (22.8)73 (26.0)55 (19.6)
 Lung cancer10 (1.8)3 (1.1)7 (2.5)
Measures of IPF severity and management considerations
 FVC (%) predicted65.6±19.166.4±19.264.8±18.9
 FEV1/FVC (%)83.0 (78.0, 87.0)82.0 (77.0, 87.0)83.0 (78.0, 86.0)
 DLCO (%) predicted41.0±15.441.4±15.440.7±15.4
 DLCO not performed54 (9.6)23 (8.2)31 (11.0)
 6MWD (m)366 (262, 445)370 (257, 447)357 (268, 442)
 Surgical lung biopsy177 (31.5)93 (33.1)84 (29.9)
 Antifibrotic therapy*330 (58.7)156 (55.5)174 (61.9)
 Pirfenidone200 (35.6)89 (31.7)111 (39.5)
 Nintedanib165 (29.4)84 (29.9)81 (28.8)
 Exertional hypoxia228 (40.6)110 (39.1)118 (42.0)
 Prescribed oxygen133 (58.3)67 (23.8)66 (23.5)
 Observed desaturation†95 (41.7)45 (16.0)50 (17.8)
GAP stage‡
 1115 (20.5)63 (22.4)52 (18.5)
 2278 (49.5)142 (50.5)136 (48.4)
 3169 (30.1)76 (27.0)93 (33.1)
  • Data presented as mean±SD, median (25th percentile, 75th percentile) or n (%).

  • *Antifibrotic therapy for at least 6 months (some patients transitioned between therapies).

  • †Observed desaturation during 6 min walk test in the absence of a prior oxygen prescription.

  • ‡GAP stage as classified by the original GAP index proposed and validated by Ley et al.5

  • DLCO, diffusion capacity for carbon monoxide; FVC, forced vital capacity; GAP, gender-age-physiology; 6MWD, 6 min walk test distance; OSA, obstructive sleep apneoa.