Table 1.
Baseline Characteristics of Study Subjects
| COPDGene NHW | COPDGene AA | ECLIPSE | GenKOLS (Norway) | |
|---|---|---|---|---|
| Sample size | 6,215 | 2,955 | 1,538 | 824 |
| Age, yr | 62.30 (55.20 to 68.80) | 53.00 (49.20 to 58.20) | 64.00 (58.00 to 69.00) | 59.50 (52.40 to 68.20) |
| Sex, male, n (%) | 3,293 (53) | 1,647 (55.7) | 996 (65) | 481 (58.4) |
| Pack-years | 42.00 (30 to 58.7) | 34.40 (22.5 to 46.55) | 43.00 (30.00 to 58.00) | 22.40 (13.61 to 34.20) |
| FEV1, %predicted | 78.30 (55.85 to 93.20) | 86.60 (71.10 to 98.95) | 48.20 (36.50 to 64.35) | 79.03 (54.75 to 93.09) |
| Total emphysema (%LAA950) | 2.78 (0.84 to 8.74) | 0.93 (0.35 to 2.75) | 14.61 (6.64 to 25.31) | 1.74 (0.47 to 7.84) |
| Emphysema distribution difference | −0.27 (−1.55 to 1.25) | −0.05 (−0.47 to 0.59) | 0.72 (−3.60 to 12.20) | −0.14 (−1.22 to 0.80) |
| Emphysema distribution ratio | 0.75 (0.41 to 1.44) | 0.85 (0.45 to 1.80) | 1.15 (0.64 to 2.11) | 0.78 (0.35 to 1.63) |
| Emphysema predominance, n | ||||
| Lower lobe predominance | 2,036 | 851 | 265 | 295 |
| Diffuse emphysema | 3,116 | 1,448 | 872 | 371 |
| Upper lobe predominance | 1,063 | 656 | 401 | 158 |
| GOLD grade, n | ||||
| PRISm | 649 | 476 | 0 | 0 |
| 0 | 2,382 | 1,658 | 144 | 398 |
| 1 | 583 | 163 | 0 | 0 |
| 2 | 1,354 | 416 | 569 | 250 |
| 3 | 838 | 183 | 634 | 124 |
| 4 | 409 | 59 | 191 | 52 |
| COPD cases (COPD GOLD 2–4) | 2,601 | 658 | 1,394 | 426 |
| Subjects with total emphysema > 5% | 2,256 | 438 | 1,234 | 254 |
Definition of abbreviations: AA = African American; COPD = chronic obstructive pulmonary disease; COPDGene = Genetic Epidemiology of COPD; ECLIPSE = Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints; GenKOLS = Genetics of Chronic Obstructive Lung Disease; GOLD = Global Initiative for Chronic Obstructive Lung Disease; NHW = non-Hispanic white; PRISm = Preserved Ratio Impaired Spirometry; %LAA950 = percentage of lung voxels with attenuation on computed tomography densitometry lower than −950 Hounsfield units.
Continuous variables are expressed as median (interquartile range).
Emphysema distribution difference is the difference between upper-third and lower-third emphysema. Emphysema distribution ratio is the ratio between upper-third and lower-third emphysema. Emphysema predominance was categorized based on the ratio between upper-third and lower-third emphysema: Subjects with emphysema ratio less than 0.5 (“lower lobe–predominant group”), subjects with emphysema ratio between 0.5 and 2 (“diffuse emphysema group”), and subjects with emphysema ratio greater than 2 (“upper lobe–predominant group”) in each of the studied cohorts.