Table 1. Patient Demographics and Preoperative Characteristics for Low Users and Super-Utilizers of Medicare in the Crude Population and the Propensity-Matched Population.
| Variable | No. (%) of Patients | |||||||
|---|---|---|---|---|---|---|---|---|
| Crude Population | Propensity-Matched Population | |||||||
| Total (n = 626 754) | Low User (n = 547 008) | Super-Utilizer (n = 79 746) | Effect Size | Total (n = 52 986) | Low User (n = 35 497) | Super-Utilizer (n = 17 489) | Effect Size | |
| Age, median (IQR), ya | 73 (69-78) | 73 (68-78) | 74 (70-79) | −0.009 | 74 (69-79) | 74 (69 -79) | 74 (69-79) | −0.002 |
| Age category, y | ||||||||
| 65-69 | 172 189 (27.5) | 154 233 (28.2) | 17 956 (22.5) | 0.059 | 12 735 (24.0) | 8799 (24.8) | 3936 (22.5) | 0.027 |
| 70-74 | 181 782 (29.0) | 160 162 (29.3) | 21 620 (27.1) | 14 358 (27.1) | 9493 (26.7) | 4865 (27.8) | ||
| 75-79 | 143 416 (22.9) | 123 613 (22.6) | 19 803 (24.8) | 12 192 (23.0) | 8014 (22.6) | 4178 (23.9) | ||
| 80-84 | 87 383 (13.9) | 73 876 (13.5) | 13 507 (16.9) | 8331 (15.7) | 5578 (15.7) | 2753 (15.7) | ||
| >84 | 41 981 (6.7) | 35 121 (6.4) | 6860 (8.6) | 5369 (10.1) | 3612 (10.2) | 1757 (10.0) | ||
| Male sexa | 249 326 (39.8) | 203 581 (37.2) | 45 745 (57.4) | 0.137 | 25 203 (47.6) | 16 758 (47.2) | 8445 (48.3) | 0.010 |
| Race/ethnicitya | ||||||||
| White | 582 559 (92.9) | 511 032 (93.4) | 71 527 (89.7) | 0.055 | 48 727 (92.0) | 32 663 (92.0) | 16 064 (91.9) | 0.003 |
| African American | 27 263 (4.3) | 21 549 (3.9) | 5714 (7.2) | 2926 (5.5) | 1944 (5.5) | 982 (5.6) | ||
| Hispanic | 1599 (0.3) | 1287 (0.2) | 312 (0.4) | 163 (0.3) | 110 (0.3) | 53 (0.3) | ||
| Other/unknown | 15 333 (2.4) | 13 140 (2.4) | 2193 (2.7) | 1170 (2.2) | 780 (2.2) | 390 (2.2) | ||
| Procedurea | ||||||||
| Colectomy | 73 427 (11.7) | 52 404 (9.6) | 21 023 (26.4) | 0.660 | 12 903 (24.4) | 8375 (23.6) | 4528 (25.9) | 0.048 |
| AAA | 14 173 (2.3) | 7549 (1.4) | 6624 (8.3) | 2733 (5.2) | 1850 (5.2) | 883 (5.0) | ||
| CABG | 33 498 (5.3) | 1983 (0.4) | 31 515 (39.5) | 2075 (3.9) | 1217 (3.4) | 858 (4.9) | ||
| Total hip arthoplasty | 162 005 (25.8) | 155 270 (28.4) | 6735 (8.4) | 11 727 (22.1) | 7874 (22.2) | 3853 (22.0) | ||
| Total knee arthoplasty | 315 697 (50.4) | 307 584 (56.2) | 8113 (10.2) | 17 417 (32.9) | 11 979 (33.7) | 5438 (31.1) | ||
| Lung resection | 27 954 (4.5) | 22 218 (4.1) | 5736 (7.2) | 6131 (11.6) | 4202 (11.8) | 1929 (11.0) | ||
| Comorbidity index, median (IQR)a | ||||||||
| Charlson | 1 (0-2) | 0 (0-2) | 4 (3-6) | −0.052 | 3 (1-5) | 2 (1-5) | 3 (2-5) | −0.007 |
| Elixhauser | 2 (1-4) | 2 (1-3) | 5 (4-7) | −0.047 | 3 (2-5) | 3 (2-5) | 3 (2-5) | −0.005 |
| CMS-HCC | 0.70 (0.41-1.25) | 0.65 (0.39-1) | 2.77 (1.66-3.95) | −0.047 | 1.31 (0.74-2.35) | 1.25 (0.71- 2.28) | 1.44 (0.84-2.47) | −0.006 |
Abbreviations: AAA, abdominal aortic aneurysm; CABG, coronary artery bypass graft; CMS-HCC, Centers for Medicare & Medicaid Services–Hierarchical Condition Category; IQR, interquartile range.
a
Used in the propensity-matching analysis.