Table 1.
Baseline characteristics of individuals by RDW categories.
Values are mean (standard deviation), median (inter-quartile range) or number (percentage). RDW, red blood cell distribution width. APACHE, acute physiology, age and chronic health evaluation.
| RDW, % | <13.0 | 13.0–13.4 | 13.5–13.9 | 14.0–14.4 | 14.5–14.9 | ≥15 | P value |
|---|---|---|---|---|---|---|---|
| N (%) | 5684 (12.0) | 6944 (14.7) | 7130 (15.1) | 6160 (13.0) | 4922 (10.4) | 16,426 (34.8) | |
| Age, years | 61.4 ± 15.0 | 64.6 ± 14.1 | 66.8 ± 14.2 | 68.3 ± 14.0 | 69.0 ± 13.8 | 68.6 ± 14.3 | <0.001 |
| Male, n (%) | 3751 (66.0) | 4502 (64.8) | 4417 (61.9) | 3524 (57.2) | 2765 (56.2) | 8659 (52.7) | <0.001 |
| Ethnicity | <0.001 | ||||||
| Caucasian, n (%) | 4632 (81.5) | 5704 (82.1) | 5727 (80.3) | 4840 (78.6) | 3786 (76.9) | 12,157 (74.0) | |
| Other/unknown, n (%) | 1052 (18.5) | 1240 (17.9) | 1403 (19.7) | 1320 (21.4) | 1136 (23.1) | 4269 (26.0) | |
| Heart rate, bpm | 96 ± 31 | 92 ± 31 | 91 ± 32 | 91 ± 32 | 91 ± 33 | 97 ± 32 | <0.001 |
| Mean blood pressure, mmHg | 85 ± 42 | 86 ± 42 | 89 ± 43 | 92 ± 43 | 93 ± 43 | 94 ± 43 | <0.001 |
| Body mass index, kg/m2 | 28.5 ± 5.9 | 29.0 ± 6.2 | 29.3 ± 6.6 | 29.3 ± 6.9 | 29.5 ± 7.2 | 29.6 ± 8.0 | <0.001 |
| Severity score | |||||||
| Glasgow coma scale | 12 ± 4 | 13 ± 4 | 13 ± 4 | 13 ± 3 | 13 ± 3 | 13 ± 4 | <0.001 |
| APACHE score | 51 (37–68) | 52 (37–68) | 52 (38–68) | 53 (38–70) | 54 (40–71) | 57 (41–75) | <0.001 |
| Laboratory measurement | |||||||
| White blood cell, × 109/L | 10.3 ± 5.2 | 10.8 ± 5.3 | 10.8 ± 5.1 | 10.9 ± 5.1 | 11.1 ± 5.0 | 12.3 ± 5.6 | <0.001 |
| Hemoglobin, g/dL | 10.6 ± 2.2 | 11.4 ± 2.2 | 11.7 ± 2.2 | 12.0 ± 2.1 | 12.0 ± 2.2 | 11.6 ± 2.2 | <0.001 |
| Hematocrit, % | 31.8 ± 6.4 | 34.1 ± 6.3 | 35.2 ± 6.2 | 36.0 ± 6.1 | 36.1 ± 6.2 | 35.3 ± 6.2 | <0.001 |
| Mean corpuscular volume, fL | 91.6 ± 6.3 | 91.2 ± 6.0 | 90.6 ± 5.9 | 90.6 ± 5.9 | 90.2 ± 5.9 | 89.1 ± 6.5 | <0.001 |
| Albumin, g/L | 28.9 ± 6.6 | 30.7 ± 5.8 | 31.3 ± 5.6 | 31.3 ± 5.8 | 31.7 ± 5.8 | 30. ±6.3 | <0.001 |
| Creatinine, mg/dL | 1.1 (0.4–9.7) | 1.0 (0.5–10.0) | 1.0 (0.4–9.3) | 1.0 (0.4–10.0) | 1.0 (0.4–9.0) | 1.0 (0.5–10.1) | <0.001 |
| Primary diagnosis | |||||||
| Acute myocardial infarction, n (%) | 929 (16.3) | 1176 (16.9) | 1087 (15.2) | 820 (13.3) | 481 (9.8) | 1141 (6.9) | <0.001 |
| Ischemic stroke, n (%) | 788 (13.9) | 835 (12.0) | 832 (11.7) | 626 (10.2) | 435 (8.8) | 1098 (6.7) | <0.001 |
| Intracerebral hemorrhage or subarachnoid hemorrhage, n (%) | 470 (8.3) | 452 (6.5) | 429 (6.0) | 317 (5.1) | 243 (4.9) | 490 (3.0) | <0.001 |
| Congestive heart failure, n (%) | 132 (2.3) | 223 (3.2) | 356 (5.0) | 455 (7.4) | 536 (10.9) | 3065 (18.7) | <0.001 |
| Cardiac arrest or ventricular arrhythmia, n (%) | 360 (6.3) | 465 (6.7) | 497 (7.0) | 444 (7.2) | 413 (8.4) | 1886 (11.5) | <0.001 |
| Atrial or other arrhythmia, n (%) | 280 (4.9) | 352 (5.1) | 444 (6.2) | 383 (6.2) | 347 (7.0) | 1437 (8.7) | <0.001 |
| Hypertension, n (%) | 132 (2.3) | 196 (2.8) | 198 (2.8) | 201 (3.3) | 132 (2.7) | 497 (3.0) | 0.037 |
| Cardiac surgery, n (%) | 1126 (19.8) | 1398 (20.1) | 1370 (19.2) | 1220 (19.8) | 967 (19.6) | 2451 (14.9) | <0.001 |
| Cardiogenic shock, n (%) | 29 (0.5) | 33 (0.5) | 47 (0.7) | 40 (0.6) | 57 (1.2) | 218 (1.3) | 0.012 |
| Cardiomyopathy, n (%) | 24 (0.4) | 29 (0.4) | 37 (0.5) | 47 (0.8) | 43 (0.9) | 241 (1.5) | <0.001 |
| Pulmonary embolism or deep venous thrombosis, n (%) | 195 (3.4) | 243 (3.5) | 227 (3.2) | 211 (3.4) | 182 (3.7) | 637 (3.9) | 0.127 |
| Aortic aneurysm or dissection, n (%) | 110 (1.9) | 156 (2.2) | 175 (2.5) | 187 (3.0) | 138 (2.8) | 341 (2.1) | <0.001 |
| Pre-admission comorbidities | |||||||
| Hypertension, n (%) | 3346 (58.9) | 4179 (60.2) | 4229 (59.3) | 3638 (59.1) | 2878 (58.5) | 9445 (57.5) | 0.004 |
| Stroke or TIA, n (%) | 594 (10.5) | 800 (11.5) | 851 (11.9) | 737 (12.0) | 601 (12.2) | 2130 (13.0) | <0.001 |
| Prior myocardial infarction, n (%) | 823 (14.5) | 1050 (15.1) | 1046 (14.7) | 845 (13.7) | 668 (13.6) | 2016 (12.3) | <0.001 |
| Percutaneous coronary intervention, n (%) | 601 (10.6) | 802 (11.5) | 783 (11.0) | 681 (11.1) | 482 (9.8) | 1538 (9.4) | <0.001 |
| Coronary artery bypass grafting, n (%) | 515 (9.1) | 651 (9.4) | 645 (9.0) | 478 (7.8) | 377 (7.7) | 1044 (6.4) | <0.001 |
| Chronic heart failure, n (%) | 1301 (22.9) | 1538 (22.1) | 1453 (20.4) | 1164 (18.9) | 910 (18.5) | 2968 (18.1) | <0.001 |
| Atrial fibrillation, n (%) | 980 (17.2) | 1127 (16.2) | 1033 (14.5) | 820 (13.3) | 640 (13.0) | 2046 (12.5) | <0.001 |
| Diabetes mellitus, n (%) | 723 (12.7) | 836 (12.0) | 935 (13.1) | 753 (12.2) | 625 (12.7) | 2230 (13.6) | 0.013 |
| Chronic obstructive pulmonary disease, n (%) | 688 (12.1) | 831 (12.0) | 887 (12.4) | 787 (12.8) | 604 (12.3) | 2153 (13.1) | 0.133 |
| Renal insufficiency, n (%) | 999 (17.6) | 1111 (16.0) | 1025 (14.4) | 780 (12.7) | 595 (12.1) | 1948 (11.9) | <0.001 |
| Dementia, n (%) | 98 (1.7) | 171 (2.5) | 155 (2.2) | 169 (2.7) | 136 (2.8) | 421 (2.6) | <0.001 |
| Cancer, n (%) | 927 (16.3) | 855 (12.3) | 760 (10.7) | 637 (10.3) | 500 (10.2) | 1755 (10.7) | <0.001 |
| Theraputics | |||||||
| Mechanical ventilation, n (%) | 2136 (37.6) | 2017 (29.0) | 1709 (24.0) | 1355 (22.0) | 963 (19.6) | 3418 (20.8) | <0.001 |
| Dialysis, n (%) | 299 (5.3) | 316 (4.6) | 289 (4.1) | 231 (3.8) | 158 (3.2) | 532 (3.2) | <0.001 |
| Red blood cell transfusion, n (%) | 262 (4.6) | 210 (3.0) | 145 (2.0) | 101 (1.6) | 71 (1.4) | 272 (1.7) | <0.001 |
| Anticoagulants, n (%) | 1259 (22.1) | 1620 (23.3) | 1695 (23.8) | 1376 (22.3) | 1073 (21.8) | 3509 (21.4) | <0.001 |
| Antiplatelet agents, n (%) | 1374 (24.2) | 1965 (28.3) | 2077 (29.1) | 1773 (28.8) | 1437 (29.2) | 4376 (26.6) | <0.001 |
| Lipid-lowering agents, n (%) | 1674 (29.5) | 2371 (34.1) | 2555 (35.8) | 2182 (35.4) | 1737 (35.3) | 5288 (32.2) | <0.001 |
| Length of stay, days | 3.9 (2.1–6.1) | 4.0 (2.2–6.4) | 4.2 (2.3–7.0) | 4.6 (2.6–7.2) | 4.9 (2.8–8.0) | 5.4 (3.0–9.1) | <0.001 |
| All-cause death, n (%) | 249 (4.4) | 354 (5.1) | 414 (5.8) | 432 (7.0) | 422 (8.6) | 2199 (13.4) | <0.001 |