Table 1 Demographic and Comorbidities of Patients with Chronic Obstructive Pulmonary Disease (COPD), according to the number of COPD-related emergency department visits in one year
|  | 1 ED visit | 2 ED visits | ≥ 3 ED visits |  |
|---|---|---|---|---|
Variables* | (n = 69,398) | (n = 17,005) | (n = 11,877) | P value†|
Age (y), median (IQR) | 69 (58–79) | 69 (59–78) | 67 (58–76) | <0.001‡ |
 40-54 years | 11,922 (17) | 2595 (15) | 2010 (17) | <0.001 |
 55-64 years | 14,807 (21) | 3815 (22) | 3288 (28) |  |
 65-74 years | 17,049 (25) | 4575 (27) | 3287 (28) |  |
 75-84 years | 16,788 (24) | 4160 (24) | 2441 (21) |  |
 85 years and older | 8832 (13) | 1860 (11) | 851 (7) |  |
Male sex | 30,633 (44) | 7632 (45) | 5527 (47) | <0.001 |
Race/ethnicity | Â | Â | Â | <0.001 |
 Non-hispanic white | 51,557 (74) | 12,746 (75) | 8713 (73) |  |
 Non-hispanic black | 6349 (9) | 1702 (10) | 1577 (13) |  |
 Hispanic | 7715 (11) | 1732 (10) | 1068 (9) |  |
 Other | 2484 (4) | 569 (3) | 337 (3) |  |
 Missing | 1303 (2) | 256 (2) | 182 (2) |  |
Insurance status | Â | Â | Â | Â |
 Medicare | 46,174 (67) | 11,829 (70) | 7793 (66) | <0.001 |
 Medicaid | 8092 (12) | 2417 (14) | 2413 (20) |  |
 Private | 7931 (11) | 1299 (8) | 729 (6) |  |
 Self-pay | 4322 (6) | 71 (4) | 431 (4) |  |
 Other | 2870 (4) | 699 (4) | 508 (4) |  |
Quartiles for median household income of patient’s ZIP code |  | <0.001 | ||
 1 (lowest) | 22,390 (32) | 5749 (34) | 4415 (37) |  |
 2 | 19,307 (28) | 4800 (28) | 3325 (28) |  |
 3 | 15,904 (23) | 3797 (22) | 2497 (21) |  |
 4 (highest) | 10,524 (15) | 2308 (14) | 1372 (12) |  |
 Missing | 1273 (2) | 351 (2) | 268 (2) |  |
Patient residence | Â | Â | Â | <0.001 |
 Counties of ≥ 1 million population | 42,303 (61) | 10,245 (60) | 7123 (60) |  |
 Counties of 250,000-999,999 population | 17,379 (25) | 4319 (25) | 2983 (25) |  |
 Counties of 50,000-249,999 population | 4103 (6) | 1053 (6) | 750 (6) |  |
 Counties of < 50,000 population | 5590 (8) | 1335 (8) | 956 (8) |  |
State | Â | Â | Â | 0.02 |
 California | 33,741 (49) | 8297 (49) | 5942 (50) |  |
 Florida | 35,657 (51) | 8708 (51) | 5935 (50) |  |
 Any comorbidities | 54,633 (79) | 13,888 (82) | 9644 (81) | <0.001 |
Selected comorbidities§ |  |  |  |  |
 Congestive heart failure | 13,607 (20) | 3831 (23) | 2708 (23) | <0.001 |
 Pulmonary circulation disorders | 674 (1) | 269 (2) | 198 (2) | <0.001 |
 Diabetes, uncomplicated | 14,813 (21) | 3931 (23) | 2939 (25) | <0.001 |
 Obesity | 7195 (10) | 1935 (11) | 1437 (12) | <0.001 |
 Depression | 6357 (9) | 1886 (11) | 1479 (12) | <0.001 |
 Psychoses | 3233 (5) | 1001 (6) | 847 (7) | <0.001 |
 Drug abuse | 1430 (2) | 458 (3) | 528 (4) | <0.001 |