Characteristics of patients based on identification strategy
| Union | ICD-CM codes only n=44 839 | MS-DRG codes only n=73 | Overlap | P value | |
| (ICD-CM or MS-DRG) n=365 099 | (ICD-CM and MS-DRG) n=320 187 | ||||
| Patient characteristics | |||||
| Median age (IQR) | 73 (62–83) | 71 (61–81) | 67 (55–81) | 73 (62–83) | <0.001 |
| Female, n (%) | 182 588 (50.0) | 20 249 (45.2) | 36 (49.3) | 162 303 (50.7) | <0.001 |
| Race/ethnicity, n (%) | |||||
| White | 201 704 (55.2) | 25 514 (56.9) | 36 (49.3) | 176 154 (55.0) | <0.001 |
| Black | 37 780 (10.4) | 4571 (10.2) | 7 (9.6) | 33 202 (10.4) | |
| Asian/Pacific Islander | 38 589 (10.6) | 3788 (8.4) | 4 (5.5) | 34 797 (10.9) | |
| Hispanic | 72 226 (19.8) | 8767 (19.6) | 23 (31.5) | 63 436 (19.8) | |
| Other | 12 137 (3.3) | 1636 (3.6) | 2 (2.7) | 10 499 (3.3) | |
| Missing | 2663 (0.7) | 563 (1.3) | 1 (1.4) | 2099 (0.6) | |
| Expected payer, n (%) | |||||
| Medicare | 232 145 (63,6) | 19 162 (42.7) | 37 (50.7) | 212 946 (66.5) | <0.001 |
| Medicaid | 43 287 (11.9) | 4804 (10.7) | 13 (17.8) | 38 470 (12.0) | |
| Private insurance | 71 343 (19.5) | 18 436 (41.1) | 22 (30.1) | 52 885 (16.5) | |
| Self-pay | 9050 (2.5) | 1461 (3.3) | 0 (0.0) | 7589 (2.4) | |
| Other | 9274 (2.5) | 976 (2.2) | 1 (1.4) | 8297 (2.6) | |
| Rural residence, n (%) | 10 487 (2.9) | 2298 (5.1) | 1 (1.4) | 8188 (2.6) | <0.001 |
| Hospital characteristics* | |||||
| Rural location, n (%) | 7807 (2.1) | 2150 (4.8) | 0 (0.0) | 5657 (1.8) | <0.001 |
| Academic, n (%) | 52 617 (14.4) | 5604 (12.5) | 12 (16.4) | 47 001 (14.7) | <0.001 |
| Stroke centre status, n (%) | |||||
| None | 60 459 (16.5) | 9441 (21.0) | 3 (4.1) | 51 015 (15.9) | <0.001 |
| Acute Stroke Ready Hospital | 975 (0.3) | 261 (0.6) | 0 (0.0) | 714 (0.2) | |
| Primary Stroke Center | 239 603 (65.6) | 28 504 (63.6) | 58 (79.5) | 211 041 (65.9) | |
| Thrombectomy-capable or Comprehensive Stroke Center | 64 062 (17.6) | 6633 (14.8) | 12 (16.4) | 57 417 (18.0) | |
*Hospital characteristics are presented at the visit level.
ICD-CM, International Classification of Disease, clinical modification; MS-DRG, Medicare Severity-Diagnosis-related Group.