Table 1.
Characteristics of Participants Included in This Study
| Characteristic | COPDGene |
ECLIPSE (n = 468) | P Value | |
|---|---|---|---|---|
| Training Sample (n = 1,945) | Testing Sample (n = 624) | |||
| Age, yr, mean (SD) | 65.31 (8.70) | 66.05 (8.28) | 64.43 (6.09) | 0.006 |
| Sex, F, n (%) | 942 (48.4) | 299 (47.9) | 156 (33.3) | <0.001 |
| Race, n (%) | 486 (25.0) | 156 (25.0) | 0 (0.0) | <0.001 |
| Height, cm, mean (SD) | 169.56 (9.56) | 169.46 (9.49) | 169.31 (8.61) | 0.874 |
| BMI, kg/m2, mean (SD) | 28.83 (6.19) | 29.25 (6.69) | 27.11 (5.46) | <0.001 |
| Pack-years of smoking, mean (SD) | 43.92 (23.71) | 44.27 (24.04) | 49.33 (26.87) | <0.001 |
| Current smoking, n (%) | 700 (36.0) | 216 (34.6) | 70 (15.0) | <0.001 |
| FEV1% predicted, mean (SD) | 78.84 (24.25) | 77.79 (24.08) | 44.22 (14.64) | <0.001 |
| FEV1/FVC, mean (SD) | 0.68 (0.15) | 0.68 (0.15) | 0.44 (0.11) | <0.001 |
| % LAA <−950 HU, median (IQR)* | 1.63 (0.51–5.20) | 1.51 (0.45–5.31) | 17.66 (9.98–26.74) | <0.001 |
| Perc15, mean (SD)* | −916.40 (29.14) | −914.72 (31.03) | −959.03 (49.24) | <0.001 |
| Pi10, mean (SD) | 2.25 (0.57) | 2.26 (0.58) | 4.40 (0.20) | <0.001 |
| WA%, mean (SD) | 49.85 (8.24) | 50.10 (8.56) | 65.37 (3.76) | <0.001 |
| Primary outcomes | ||||
| Moderate to severe COPD, n (%) | 658 (33.8) | 209 (33.5) | 468 (100.0) | <0.001 |
| FEV1 decline, ml/yr, mean (SD) | −42.09 (55.30) | −42.52 (59.08) | −30.58 (71.82) | 0.004 |
Definition of abbreviations: % LAA = % low-attenuation area; BMI = body mass index; COPD = chronic obstructive pulmonary disease; COPDGene = Genetic Epidemiology of COPD; ECLIPSE = Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points; HU = Hounsfield units; IQR = interquartile range; Perc15 = 15th percentile of the lung density histogram on inspiratory scans; Pi10 = square root of wall area of a hypothetical airway with internal perimeter of 10 mm; WA% = wall area percent.
P values indicate comparisons across COPDGene samples and ECLIPSE.
*
% LAA <−950 HU and Perc15 were calculated using Thirona at phase 2 (5-yr follow-up) in COPDGene and Slicer in ECLIPSE.