Table 1.
Personal and clinical characteristics of 4297 patients admitted to hospital with coronavirus disease 2019 (covid-19) who received prophylactic anticoagulation within 24 hours of hospital admission, before and after weighting. Values are numbers (percentages) unless stated otherwise
| Characteristics | Unweighted | IPT weighted* | |||||
|---|---|---|---|---|---|---|---|
| No anticoagulation (n=670) | Prophylactic anticoagulation (n=3627) | SMD | No anticoagulation (n=2141) | Prophylactic anticoagulation (n=2156) | SMD | ||
| Personal characteristics | |||||||
| Median (interquartile range) age (years) | 69.0 (58.0-76.5) | 68.1 (58.2-74.8) | 0.04 | 69.4 (59.7-76.5) | 68.3 (58.2-75.0) | 0.04 | |
| Age groups (years): | |||||||
| 20-49 | 89 (13.3) | 446 (12.3) | 0.03 | 239 (11.2) | 265 (12.3) | 0.04 | |
| 50-59 | 105 (15.7) | 619 (17.1) | 0.04 | 313 (14.6) | 363 (16.8) | 0.06 | |
| 60-69 | 161 (24.0) | 951 (26.2) | 0.05 | 554 (25.9) | 558 (25.9) | 0.00 | |
| 70-79 | 188 (28.1) | 1056 (29.1) | 0.02 | 652 (30.5) | 626 (29.0) | 0.03 | |
| ≥80 | 127 (19.0) | 555 (15.3) | 0.10 | 383 (17.9) | 343 (15.9) | 0.05 | |
| Race or ethnicity: | |||||||
| White | 256 (38.2) | 1347 (37.1) | 0.02 | 832 (38.9) | 806 (37.4) | 0.03 | |
| Black | 291 (43.4) | 1649 (45.5) | 0.04 | 940 (43.9) | 974 (45.2) | 0.03 | |
| Hispanic | 74 (11.0) | 432 (11.9) | 0.03 | 238 (11.1) | 252 (11.7) | 0.02 | |
| Other | 22 (3.3) | 102 (2.8) | 0.03 | 76 (3.6) | 63 (2.9) | 0.04 | |
| Unknown | 27 (4.0) | 97 (2.7) | 0.08 | 55 (2.6) | 61 (2.8) | 0.02 | |
| Men | 620 (92.5) | 3395 (93.6) | 0.04 | 2019 (94.3) | 2014 (93.4) | 0.04 | |
| Urban residence | 587 (87.6) | 3181 (87.7) | 0.00 | 1915 (89.5) | 1893 (87.8) | 0.05 | |
| Census region: | |||||||
| Midwest | 79 (11.8) | 724 (20.0) | 0.22 | 343 (16.0) | 400 (18.6) | 0.07 | |
| Northeast | 139 (20.7) | 622 (17.1) | 0.09 | 432 (20.2) | 383 (17.8) | 0.06 | |
| South | 314 (46.9) | 1703 (47.0) | 0.00 | 998 (46.6) | 1012 (46.9) | 0.01 | |
| West | 138 (20.6) | 578 (15.9) | 0.12 | 367 (17.2) | 361 (16.7) | 0.01 | |
| Month of admission: | |||||||
| March | 116 (17.3) | 518 (14.3) | 0.08 | 323 (15.1) | 316 (14.7) | 0.01 | |
| April | 169 (25.2) | 868 (23.9) | 0.03 | 491 (22.9) | 522 (24.2) | 0.03 | |
| May | 70 (10.4) | 429 (11.8) | 0.04 | 277 (12.9) | 250 (11.6) | 0.04 | |
| June | 110 (16.4) | 616 (17.0) | 0.02 | 361 (16.9) | 364 (16.9) | 0.00 | |
| July | 205 (30.6) | 1196 (33.0) | 0.05 | 689 (32.2) | 704 (32.6) | 0.01 | |
| Clinical conditions | |||||||
| Acute myocardial infarction | 11 (1.6) | 66 (1.8) | 0.01 | 45 (2.1) | 39 (1.8) | 0.02 | |
| Asthma | 33 (4.9) | 176 (4.9) | 0.00 | 117 (5.5) | 105 (4.9) | 0.03 | |
| Cancer, any | 97 (14.5) | 494 (13.6) | 0.02 | 318 (14.9) | 298 (13.8) | 0.03 | |
| Cerebrovascular disease | 85 (12.7) | 369 (10.2) | 0.08 | 223 (10.4) | 230 (10.7) | 0.01 | |
| Chronic kidney disease | 136 (20.3) | 694 (19.1) | 0.03 | 436 (20.4) | 421 (19.5) | 0.02 | |
| COPD | 105 (15.7) | 544 (15.0) | 0.02 | 359 (16.8) | 328 (15.2) | 0.04 | |
| Coronary artery disease | 25 (3.7) | 90 (2.5) | 0.07 | 65 (3.0) | 59 (2.7) | 0.02 | |
| Dementia | 104 (15.5) | 378 (10.4) | 0.15 | 261 (12.2) | 244 (11.3) | 0.03 | |
| Diabetes | 269 (40.1) | 1573 (43.4) | 0.07 | 859 (40.1) | 924 (42.9) | 0.06 | |
| Heart failure | 77 (11.5) | 375 (10.3) | 0.04 | 265 (12.4) | 232 (10.8) | 0.05 | |
| Hypertension | 446 (66.6) | 2470 (68.1) | 0.03 | 1380 (64.5) | 1462 (67.8) | 0.07 | |
| Liver disease | 71 (10.6) | 322 (8.9) | 0.06 | 209 (9.8) | 199 (9.2) | 0.02 | |
| Peripheral arterial disease | 70 (10.4) | 387 (10.7) | 0.01 | 236 (11.0) | 229 (10.6) | 0.01 | |
| Charlson comorbidity index score: | |||||||
| 0 | 130 (19.4) | 765 (21.1) | 0.04 | 404 (18.9) | 450 (20.9) | 0.05 | |
| 1 | 110 (16.4) | 723 (19.9) | 0.09 | 388 (18.1) | 423 (19.6) | 0.04 | |
| 2 | 119 (17.8) | 657 (18.1) | 0.01 | 403 (18.8) | 384 (17.8) | 0.03 | |
| 3 | 74 (11.0) | 394 (10.9) | 0.01 | 252 (11.8) | 235 (10.9) | 0.03 | |
| 4 | 69 (10.3) | 324 (8.9) | 0.05 | 217 (10.2) | 194 (9.0) | 0.04 | |
| ≥5 | 168 (25.1) | 764 (21.1) | 0.10 | 476 (22.2) | 470 (21.8) | 0.01 | |
| Drug history | |||||||
| ACE inhibitor | 119 (17.8) | 807 (22.2) | 0.11 | 422 (19.7) | 463 (21.5) | 0.04 | |
| ARB | 78 (11.6) | 481 (13.3) | 0.05 | 261 (12.2) | 283 (13.1) | 0.03 | |
| NSAID | 144 (21.5) | 731 (20.2) | 0.03 | 408 (19.1) | 438 (20.3) | 0.03 | |
| Oral corticosteroid | 156 (23.3) | 875 (24.1) | 0.02 | 514 (24.0) | 516 (24.0) | 0.00 | |
| In-hospital treatments | |||||||
| Dexamethasone: | |||||||
| <24 hours | 74 (11.0) | 588 (16.2) | 0.15 | 309 (14.4) | 332 (15.4) | 0.03 | |
| >24 hours | 115 (17.2) | 892 (24.6) | 0.18 | 463 (21.6) | 508 (23.6) | 0.05 | |
| Remdesivir: | |||||||
| <24 hours | 35 (5.2) | 437 (12.0) | 0.24 | 204 (9.5) | 236 (10.9) | 0.05 | |
| >24 hours | 89 (13.3) | 791 (21.8) | 0.23 | 341 (15.9) | 447 (20.7) | 0.12 | |
| Substance use | |||||||
| Alcohol consumption status: | |||||||
| Abstinent | 51 (7.6) | 300 (8.3) | 0.02 | 178 (8.3) | 177 (8.2) | 0.00 | |
| Low risk | 360 (53.7) | 1831 (50.5) | 0.07 | 1059 (49.4) | 1098 (50.9) | 0.03 | |
| At risk | 148 (22.1) | 965 (26.6) | 0.11 | 574 (26.8) | 557 (25.8) | 0.02 | |
| Hazardous | 28 (4.2) | 161 (4.4) | 0.01 | 79 (3.7) | 94 (4.4) | 0.03 | |
| Alcohol use disorder | 3 (0.4) | 19 (0.5) | 0.01 | 11 (0.5) | 11 (0.5) | 0.00 | |
| Missing | 80 (11.9) | 351 (9.7) | 0.07 | 241 (11.3) | 219 (10.1) | 0.04 | |
| Smoking status: | |||||||
| Never | 17 (2.5) | 63 (1.7) | 0.06 | 42 (2.0) | 41 (1.9) | 0.00 | |
| Former | 258 (38.5) | 1431 (39.5) | 0.02 | 753 (35.1) | 842 (39.1) | 0.08 | |
| Current | 225 (33.6) | 1355 (37.4) | 0.08 | 905 (42.3) | 793 (36.8) | 0.11 | |
| Missing | 170 (25.4) | 778 (21.5) | 0.09 | 442 (20.6) | 479 (22.2) | 0.04 | |
| Vital signs | |||||||
| Body mass index: | |||||||
| <26 | 206 (30.7) | 938 (25.9) | 0.11 | 630 (29.4) | 576 (26.7) | 0.06 | |
| 26-32 | 258 (38.5) | 1436 (39.6) | 0.02 | 940 (43.9) | 854 (39.6) | 0.09 | |
| ≥33 | 169 (25.2) | 1113 (30.7) | 0.12 | 494 (23.1) | 637 (29.5) | 0.15 | |
| Missing | 37 (5.5) | 140 (3.9) | 0.08 | 78 (3.6) | 89 (4.1) | 0.03 | |
| Oxygen saturation (%): | |||||||
| <93 | 72 (10.7) | 582 (16.0) | 0.16 | 315 (14.7) | 329 (15.2) | 0.02 | |
| 93-96 | 182 (27.2) | 1147 (31.6) | 0.10 | 669 (31.3) | 666 (30.9) | 0.01 | |
| ≥96 | 396 (59.1) | 1775 (48.9) | 0.21 | 1077 (50.3) | 1091 (50.6) | 0.01 | |
| Missing | 20 (3.0) | 123 (3.4) | 0.02 | 80 (3.7) | 71 (3.3) | 0.02 | |
| Pulse (beats/min): | |||||||
| <90 | 438 (65.4) | 2200 (60.7) | 0.10 | 1327 (62.0) | 1327 (61.6) | 0.01 | |
| ≥90 | 232 (34.6) | 1427 (39.3) | 0.10 | 814 (38.0) | 828 (38.4) | 0.01 | |
| Systolic blood pressure (mm Hg): | |||||||
| <140 | 446 (66.6) | 2360 (65.1) | 0.03 | 1347 (62.9) | 1405 (65.2) | 0.05 | |
| ≥140 | 224 (33.4) | 1267 (34.9) | 0.03 | 794 (37.1) | 751 (34.8) | 0.05 | |
| Temperature (°C): | |||||||
| ≤37 | 356 (53.1) | 1701 (46.9) | 0.12 | 1045 (48.8) | 1033 (47.9) | 0.02 | |
| 37-37.9 | 244 (36.4) | 1292 (35.6) | 0.02 | 737 (34.4) | 771 (35.8) | 0.03 | |
| ≥38 | 70 (10.4) | 634 (17.5) | 0.20 | 359 (16.8) | 352 (16.3) | 0.01 | |
IPT=inverse probability of treatment; SMD=absolute value of the standardized mean difference; COPD=chronic obstructive pulmonary disease; ACE=angiotensin converting enzyme; ARB=angiotensin II receptor blocker; NSAID=non-steroidal anti-inflammatory drug.
*
Counts after IPT weighting were calculated by multiplying weights by constant factor k, where k was the ratio of observed sample size to number in the pseudopopulation after weighting; in this study, k=4297/8576.