Table 1. Patient Characteristics of the Study Sample by Perioperative Red Blood Cell Transfusion Statusa.
| Clinical Variable | No. (%) of Patients | ||
|---|---|---|---|
| Overall (N = 750 937) | Transfusion Group (n = 47 410) | Nontransfusion Group (n = 703 527) | |
| Age group, y | |||
| 18-44 | 188 796 (25.1) | 4609 (9.7) | 184 187 (26.2) |
| 45-60 | 236 902 (31.5) | 11 158 (23.5) | 225 744 (32.1) |
| >60 | 325 239 (43.3) | 31 643 (66.7) | 293 596 (41.7) |
| Sexb | |||
| Male | 324 209 (43.2) | 20 612 (43.5) | 303 597 (43.2) |
| Female | 426 727 (56.8) | 26 798 (56.5) | 399 929 (56.8) |
| Race | |||
| White | 551 935 (73.5) | 34 027 (71.8) | 517 908 (73.6) |
| Black or African American | 75 885 (10.1) | 6221 (13.1) | 69 664 (9.9) |
| Asian | 21 081 (2.8) | 1480 (3.1) | 19 601 (2.8) |
| Other | 8494 (1.1) | 460 (1.0) | 8034 (1.1) |
| Unknown | 93 542 (12.5) | 5222 (11.0) | 88 320 (12.6) |
| BMI | |||
| Underweight (<18.5) | 12 357 (1.6) | 1997 (4.2) | 10 360 (1.5) |
| Normal weight (18.5-24.9) | 179 533 (23.9) | 14 717 (31.0) | 164 816 (23.4) |
| Overweight (25.0-29.9) | 230 320 (30.7) | 13 666 (28.8) | 216 654 (30.8) |
| Obese | |||
| Class 1 (30.0-34.9) | 155 134 (20.7) | 8235 (17.4) | 146 899 (20.9) |
| Class 2 (35.0-39.9) | 81 949 (10.9) | 3950 (8.3) | 77 999 (11.1) |
| Class 3 (≥40.0) | 76 632 (10.2) | 3294 (6.9) | 73 338 (10.4) |
| Unknown | 15 012 (2.0) | 1551 (3.3) | 13 461 (1.9) |
| Functional health status before surgery | |||
| Independent | 726 360 (96.7) | 42 283 (89.2) | 684 077 (97.2) |
| Partially dependent | 16 006 (2.1) | 3755 (7.9) | 12 251 (1.7) |
| Totally dependent | 3184 (0.4) | 937 (2.0) | 2247 (0.3) |
| Unknown | 5387 (0.7) | 435 (0.9) | 4952 (0.7) |
| ASA class | |||
| No disturbance (1) | 69 685 (9.3) | 528 (1.1) | 69 157 (9.8) |
| Mild disturbance (2) | 337 688 (45.0) | 8742 (18.4) | 328 946 (46.8) |
| Severe disturbance (3) | 296 037 (39.4) | 25 493 (53.8) | 270 544 (38.5) |
| Life-threatening (4) | 44 179 (5.9) | 11 762 (24.8) | 32 417 (4.6) |
| Moribund (5) | 1343 (0.2) | 808 (1.7) | 535 (0.1) |
| Unknown | 2005 (0.3) | 77 (0.2) | 1928 (0.3) |
| Hospital length of stay, d | |||
| 0-1 | 372 952 (49.7) | 1316 (2.8) | 371 636 (52.8) |
| ≥2 | 377 369 (50.3) | 45 923 (96.9) | 331 446 (47.1) |
| Unknown | 616 (0.1) | 171 (0.4) | 445 (0.1) |
| Other medical complications | |||
| Concurrent sepsis | 13 307 (1.8) | 2886 (6.1) | 10 421 (1.5) |
| Ventilator dependence | 2557 (0.3) | 1385 (2.9) | 1172 (0.2) |
| Disseminated cancer | 17 850 (2.4) | 3688 (7.8) | 14 162 (2.0) |
| Work-related relative value units | |||
| Quartile 1 (<9.45) | 188 666 (25.1) | 2573 (5.4) | 186 093 (26.5) |
| Quartile 2 (9.45-15.38) | 191 609 (25.5) | 5185 (10.9) | 186 424 (26.5) |
| Quartile 3 (15.39-20.82) | 185 945 (24.8) | 15 285 (32.2) | 170 660 (24.3) |
| Quartile 4 (>20.82) | 184 717 (24.6) | 24 367 (51.4) | 160 350 (22.8) |
| Perioperative RBC transfusion | 47 410 (6.3) | 47 410 (100.0) | 0 |
| Preoperative only | 3605 (0.5) | 3605 (7.6) | 0 |
| Intraoperative or postoperative only | 40 015 (5.3) | 40 015 (84.4) | 0 |
| Preoperative and intraoperative or postoperative | 3790 (0.5) | 3790 (8.0) | 0 |
Abbreviations: ASA, American Society of Anesthesiology; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); RBC, red blood cell.
a
Data were derived from the American College of Surgeons’ National Surgical Quality Improvement Program database for 2014. Percentages have been rounded and may not total to 100.
b
One person had missing data for sex.