Table 2.
—Symptom and Quality-of-Life Scores by Race
| Variable | Caucasian | African American | t (df) | P Value |
| SGRQ | ||||
| Total score | 34.8 ± 21.5 | 43.2 ± 23.8 | 4.89 (306) | < .001a |
| Activity subscore | 50.5 ± 28.4 | 60.8 ± 29.7 | 4.73 (316) | < .001a |
| Impacts subscore | 24.0 ± 19.9 | 32.2 ± 23.5 | 4.86 (296) | < .001a |
| Symptom subscore | 40.5 ± 25.2 | 46.0 ± 25.3 | 2.95 (325) | .003a |
| MMRC dyspnea score | NA | .02a | ||
| 0 | 284 (27) | 45 (20) | ||
| 1 | 142 (14) | 27 (12) | ||
| 2 | 158 (15) | 35 (16) | ||
| 3 | 289 (28) | 59 (27) | ||
| 4 | 167 (16) | 55 (25) | ||
| Exacerbation frequencyb | NA | .47 | ||
| 0 | 691 (66) | 141 (63) | ||
| 1 | 191 (18) | 40 (18) | ||
| 2 | 82 (8) | 21 (9) | ||
| 3 | 37 (4) | 12 (5) | ||
| 4 | 27 (3) | 3 (1) | ||
| 5 | 3 (0.3) | 2 (1) | ||
| 6 | 18 (2) | 5 (2) | ||
| Hospitalized exacerbationc | ||||
| 0 | 878 (84) | 152 (68) | NA | < .001a |
| 1 | 171 (16) | 72 (32) | … | … |
Data are presented as mean ± SD or No. (%), unless otherwise indicated. MMRC = modified Medical Research Council; SGRQ = St. George Respiratory Questionnaire. See Table 1 legend for expansion of other abbreviations.
a
These comparisons remain statistically significant after controlling for multiple comparisons using the false discovery rate procedure.15,16
b
Number of COPD exacerbations reported in the year prior to enrollment.
c
COPD exacerbations associated with a hospitalization in the year prior to enrollment.