Table 2.
Spirometry and health outcomes according to ethnicity
| Characteristic | White-Americans N =3,506 | African-Americans N=1,860 | Mexican-Americans N =1,749 | Adjusted p-value | |||||
|---|---|---|---|---|---|---|---|---|---|
| n | Percent (95%CI) | n | Percent (95%CI) | n | Percent (95%CI) | W vs. A | W vs. M | A vs. M | |
| Spirometry * | |||||||||
| Normal | 2,778 | 79.3 (77.8, 80.7) | 1,482 | 79.7 (77.7, 81.7) | 1,504 | 86.0 (84.3, 87.8) | 0.780 | < 0.001 | < 0.001 |
| Airflow-limitation | 531 | 15.1 (13.9, 16.4) | 230 | 12.4 (10.7, 14.0) | 144 | 8.2 (6.7, 9.8) | 0.014 | < 0.001 | 0.002 |
| Restrictive-pattern | 196 | 5.6 (4.6, 6.5) | 148 | 8.0 (6.9, 9.0) | 100 | 5.7 (4.5, 6.9) | 0.002 | 0.863 | 0.016 |
| Health outcomes | |||||||||
| Respiratory symptoms † | 1,452 | 41.5 (39.2, 43.8) | 668 | 36.0 (33.5, 38.5) | 604 | 34.6 (31.9, 37.3) | < 0.001 | < 0.001 | 0.541 |
| Deaths, n (%) ‡ | 308 | 8.8 (7.6, 10.0) | 173 | 9.3 (8.0, 10.6) | 121 | 6.9 (5.4, 8.4) | 0.632 | 0.063 | 0.039 |
Abbreviations: A, African-Americans; CI, confidence interval; NHANES III, Third National Health and Nutrition Examination Survey; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1-second; FVC, forced vital capacity; LLN, lower limit of normal; M, Mexican-Americans; W, White-Americans.
Recorded at baseline: normal spirometry was defined by FEV1/FVC and FVC, both ≥LLN; airflow-limitation by FEV1/FVC <LLN; and restrictive-pattern by FEV1/FVC ≥LLN and FVC <LLN. Missing data: White-Americans (n=1); Mexican-Americans (n=1).
Recorded at baseline: chronic cough or sputum production, dyspnea-on-exertion, or wheezing. Missing data: White-Americans (n=6); Mexican-Americans (n=3); African-American (n=4).
Over 5-years of follow-up. Vital status was missing for 3 White-Americans and 2 Mexican-Americans.