Table 1. Characteristics of Participants With COPD by Mucus Plug Score Category.
| Characteristic | Mucus plug score category (No. of lung segments with mucus plugs), No. (%) | ||
|---|---|---|---|
| 0 (n = 2585) | 1-2 (n = 953) | ≥3 (n = 825) | |
| Age, median (IQR), y | 62.4 (55.9-68.7) | 63.9 (57.6-70.6) | 65.3 (57.9-71.1) |
| Sex | |||
| Female | 1072 (41.5) | 448 (47.0) | 400 (48.5) |
| Male | 1513 (58.5) | 505 (53.0) | 425 (51.5) |
| Race and ethnicitya | |||
| Non-Hispanic Black | 636 (24.6) | 199 (20.9) | 142 (17.2) |
| Non-Hispanic White | 1949 (75.4) | 754 (79.1) | 683 (82.8) |
| BMI, median (IQR) | 27.6 (24.2-31.9) | 26.8 (23.4-31.0) | 25.5 (22.1-30.1) |
| Current smoker, No. (%) [No.] | 1155 (44.7) [2584] | 383 (40.2) | 347 (42.1) [824] |
| Pack-years of smoking, median (IQR) | 44.3 (33.2-64) | 46.1 (35.0-65.7) | 47.6 (35.0-67.6) |
| Medical history | |||
| Chronic bronchitis | 584 (22.6) | 248 (26.0) | 293 (35.5) |
| Coronary artery disease | 417 (16.1) | 154 (16.2) | 113 (13.7) |
| Asthmab | 406 (15.7) | 168 (17.6) | 187 (22.7) |
| COPD GOLD stage of severityc | |||
| 1 (Mild) | 597 (23.1) | 116 (12.2) | 53 (6.4) |
| 2 (Moderate) | 1250 (48.4) | 389 (40.8) | 248 (30.1) |
| 3 (Severe) | 523 (20.2) | 297 (31.2) | 307 (37.2) |
| 4 (Very severe) | 215 (8.3) | 151 (15.8) | 217 (26.3) |
| BODE index, median (IQR) [No.]d | 2 (0-4) [2525] | 3 (1-5) [924] | 4 (2-6) [803] |
| FEV1, L | 1.8 (1.3-2.4) | 1.4 (0.9-1.9) | 1.1 (0.8-1.6) |
| FEV1, % predicted | 65.0 (47.1-78.4) | 51.9 (36.4-69.7) | 42.1 (29.1-59.4) |
| Emphysema on CT, median (IQR) [No.], %e | 5.6 (1.8-14.9) [2466] | 9.2 (2.8-22.1) [916] | 12.4 (3.4-24.2) [787] |
| Airway wall thickness, median (IQR) [No.], mmf | 2.5 (2.1-2.9) [2466] | 2.7 (2.3-3.1) [916] | 2.9 (2.5-3.3) [787] |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); BODE, body mass index, obstruction, dyspnea, and exercise mortality risk score; COPD, chronic obstructive pulmonary disease; CT, computed tomography; FEV1, forced expiratory volume in the first second of expiration; GOLD, Global Initiative for Chronic Obstructive Lung Disease.
Race and ethnic group were reported by the participant. Only non-Hispanic Black and non-Hispanic White participants were included.
Asthma was defined as current asthma.
GOLD stages were defined with postbronchodilator FEV1 percentage of predicted (pp) values as follows: 1 (mild), FEV1 pp ≥80; 2 (moderate), FEV1 pp ≥50 to <80; 3 (severe) FEV1 pp ≥30 to <50; and 4 (very severe), FEV1 pp <30.
The multidimensional mortality BODE index is composed of 4 factors: BMI, FEV1 percentage predicted, distance walked in 6 minutes, and the modified Medical Research Council dyspnea scale. The BODE index ranges from 0 (lowest risk of death) to 10 (highest risk of death).
Emphysema on CT was measured as percentage of voxels less than −950 Hounsfield units.
Airway wall thickness was measured on CT as the square root of the wall area of an ideal 10-mm-inner-perimeter airway.