Spirometry and health outcomes according to ethnicity
| Characteristic | White Americans N=3506 | African Americans N=1860 | Mexican Americans N=1749 | Adjusted p value | |||||
|---|---|---|---|---|---|---|---|---|---|
| n | % (95% CI) | n | % (95% CI) | n | % (95% CI) | W vs A | W vs M | A vs M | |
| Spirometry* | |||||||||
| Normal | 2778 | 79.3 (77.8 to 80.7) | 1482 | 79.7 (77.7 to 81.7) | 1504 | 86.0 (84.3 to 87.8) | 0.780 | <0.001 | <0.001 |
| Airflow limitation | 531 | 15.1 (13.9 to 16.4) | 230 | 12.4 (10.7 to 14.0) | 144 | 8.2 (6.7 to 9.8) | 0.014 | <0.001 | 0.002 |
| Restrictive pattern | 196 | 5.6 (4.6 to 6.5) | 148 | 8.0 (6.9 to 9.0) | 100 | 5.7 (4.5 to 6.9) | 0.002 | 0.863 | 0.016 |
| Health outcomes | |||||||||
| Respiratory symptoms† | 1452 | 41.5 (39.2 to 43.8) | 668 | 36.0 (33.5 to 38.5) | 604 | 34.6 (31.9 to 37.3) | <0.001 | <0.001 | 0.541 |
| Deaths, n (%)‡ | 308 | 8.8 (7.6 to 10.0) | 173 | 9.3 (8.0 to 10.6) | 121 | 6.9 (5.4 to 8.4) | 0.632 | 0.063 | 0.039 |
*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, dyspnoea on exertion, or wheezing. Missing data: white Americans (n=6); Mexican Americans (n=3); African Americans (n=4).
‡Over 5 years of follow-up. Vital status was missing for three white Americans and two Mexican Americans.
A, African Americans; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LLN, lower limit of normal; M, Mexican Americans; W, white Americans.