Table 3.
Baseline patient characteristics
| Characteristic | Zero exacerbations (n=29,222) |
One exacerbation (n=13,797) |
Two exacerbations (n=4,982) |
≥Three exacerbations (n=4,458) |
Total (n=52,459) |
P-valuea |
|---|---|---|---|---|---|---|
| Age, mean (SD) | 71.29 (9.4) | 71.10 (9.2) | 70.78 (9.0) | 70.22 (8.9) | 71.10 (9.3) | <0.001 |
| Age category, years, n (%) | <0.001 | |||||
| 40–49 | 737 (2.5) | 334 (2.4) | 113 (2.3) | 93 (2.1) | 1,277 (2.4) | |
| 50–59 | 2,523 (8.6) | 1,196 (8.7) | 443 (8.9) | 420 (9.4) | 4,582 (8.7) | |
| 60–69 | 8,716 (29.8) | 4,281 (31.0) | 1,607 (32.3) | 1,517 (34.0) | 16,121 (30.7) | |
| 70–79 | 11,372 (38.9) | 5,370 (38.9) | 1,954 (39.2) | 1,749 (39.2) | 20,445 (39.0) | |
| 80–89 | 5,874 (20.1) | 2,616 (19.0) | 865 (17.4) | 679 (15.2) | 10,034 (19.1) | |
| Female, n (%) | 15,622 (53.5) | 7,748 (56.2) | 2,938 (59.0) | 2,484 (55.7) | 28,792 (54.9) | <0.001 |
| Race/ethnicity, n (%) | <0.001 | |||||
| White | 25,099 (85.9) | 12,138 (88.0) | 4,471 (89.7) | 3,991 (89.5) | 45,699 (87.1) | |
| Black | 2,868 (9.8) | 1,099 (8.0) | 327 (6.6) | 305 (6.8) | 4,599 (8.8) | |
| Hispanic | 594 (2.0) | 240 (1.7) | 67 (1.3) | 68 (1.5) | 969 (1.8) | |
| Other | 604 (2.1) | 283 (2.1) | 102 (2.0) | 81 (1.8) | 1,070 (2.0) | |
| Unknown | 57 (0.2) | 37 (0.3) | 15 (0.3) | 13 (0.3) | 122 (0.2) | |
| Geographic region, n (%) | <0.001 | |||||
| Northeast | 518 (1.8) | 254 (1.8) | 83 (1.7) | 71 (1.6) | 926 (1.8) | |
| Midwest | 6,080 (20.8) | 3,185 (23.1) | 1,163 (23.3) | 1,096 (24.6) | 11,524 (22.0) | |
| South | 20,231 (69.2) | 9,282 (67.3) | 3,368 (67.6) | 2,985 (67.0) | 35,866 (68.4) | |
| West | 2,393 (8.2) | 1,076 (7.8) | 368 (7.4) | 306 (6.9) | 4,143 (7.9) | |
| Plan characteristics, n (%) | ||||||
| LIS status | 5,763 (19.7) | 2,845 (20.6) | 1,013 (20.3) | 809 (18.1) | 10,430 (19.9) | 0.003 |
| Dual eligibility | 3,977 (13.6) | 1,898 (13.8) | 661 (13.3) | 440 (9.9) | 6,976 (13.3) | <0.001 |
| Oxygen therapy, n (%) | 3,227 (11.0) | 1,713 (12.4) | 966 (19.4) | 1,425 (32.0) | 7,331 (14.0) | <0.001 |
| Exacerbations in the preindex period | ||||||
| n (%) | 1,835 (6.3) | 1,573 (11.4) | 1,051 (21.1) | 1,824 (40.9) | 6,283 (12.0) | <0.001 |
| Mean (SD) | 0.07 (0.3) | 0.14 (0.4) | 0.30 (0.7) | 0.74 (1.1) | 0.17 (0.5) | <0.001 |
| DCCI, mean (SD) | 1.62 (1.8) | 1.61 (1.8) | 1.68 (1.7) | 1.84 (1.7) | 1.64 (1.8) | <0.001 |
| Airflow testingb, n (%) | 11,558 (39.6) | 6,536 (47.4) | 2,763 (55.5) | 2,899 (65.0) | 23,756 (45.3) | <0.001 |
Notes:
a
Univariate statistical comparisons were made among the four cohorts (zero, one, two, and ≥three exacerbations) using analysis of variance for continuous variables and chi-square tests for categorical variables;
b
measured during the preindex period and postindex period.
Abbreviations: COPD, chronic obstructive pulmonary disease; DCCI, Deyo–Charlson comorbidity index; ER, emergency room; LIS, low-income subsidy; SD, standard deviation.