Table 1.
Baseline Characteristics of the SPIROMICS Cohort
| SPIROMICS Cohort Baseline Characteristics | Ethnic Group |
||
|---|---|---|---|
| Non-Hispanic White Individuals | African Americans | Hispanics | |
| Demographics | |||
| Subjects, n | 1,693 | 385 | 90 |
| Age, yr, mean (SD)* | 65.2 (8.30) | 58.2 (8.96) | 60.8 (10.0) |
| Sex, F, n (%)* | 751 (44.4) | 207 (53.8) | 34 (37.8) |
| BMI, mean (SD) | 27.8 (5.06) | 28.0 (6.06) | 28.6 (5.29) |
| Pack-years, mean (SD)* | 51.8 (26.4) | 41.0 (17.4) | 46.8 (25.8) |
| COPD diagnosis, n (%)* | 1,191 (70.3) | 206 (53.5) | 52 (57.8) |
| COPD grade 2–4 diagnosis, n (%)* | 921 (54.4) | 167 (43.5) | 36 (40.0) |
| Post-bronchodilator pulmonary function | |||
| Baseline FEV1, % predicted, mean (SD)* | 71.8 (25.8) | 76.6 (27.1) | 80.0 (28.0) |
| Baseline FVC, % predicted, mean (SD)* | 90.3 (17.7) | 92.5 (20.1) | 94.8 (19.3) |
| FEV1/FVC ratio, %, mean (SD)* | 0.59 (0.16) | 0.64 (0.17) | 0.64 (0.17) |
| Clinical outcome measures | |||
| Hospitalization or ED visit last 12 mo, n (%) | 163 (9.75) | 80 (21.2) | 16 (18.0) |
| St. George’s Respiratory Questionnaire, mean (SD) | 32.1 (20.1) | 37.8 (20.9) | 34.5 (21.9) |
| BODE, mean (SD) | 1.51 (1.94) | 1.57 (1.91) | 1.08 (1.68) |
| 6-minute-walk distance, m, mean (SD)* | 408.5 (118.1) | 410.6 (135.5) | 408.9 (90.2) |
| COPD assessment test, mean (SD) | 13.5 (8.10) | 15.9 (8.88) | 15.4 (8.82) |
| Additional measures | |||
| Computed tomography evidence of emphysema, TLC % area < −950 HFU, mean (SD)* | 8.19 (10.2) | 7.70 (11.1) | 4.89 (7.73) |
| Computed tomography evidence of air trapping, residual volume % area < −856 HFU, mean (SD)* | 25.9 (21.0) | 22.2 (23.2) | 20.0 (21.0) |
| Computed tomography–based functional small airways disease, PRMfSAD, %, mean (SD)* | 21.9 (15.0) | 17.1 (15.7) | 16.8 (16.3) |
| Alpha-1 antitrypsin concentration, mg/ml, mean (SD)† | 1.98 (0.48) | 1.95 (0.48) | 1.80 (0.35) |
Definition of abbreviations: BMI = body mass index; BODE = body mass index, airflow obstruction, dyspnea, and exercise; COPD = chronic obstructive pulmonary disease; ED = emergency department; HFU = Hounsfield units; PRMfSAD = parametric response mapping of functional small airway disease; SPIROMICS = Subpopulations and Intermediate Outcomes Measures in COPD Study.
*
P < 0.05 for the trend between ethnic groups.
†
Serum alpha-1 antitypsin levels were measured in a subgroup of 1,097 non-Hispanic white individuals, 231 African Americans, and 63 Hispanics.