Table 1.
Patient demographics
| Variable | Per-protocol (n = 616) | Off-protocol (n = 187) | p-value |
|---|---|---|---|
| Age (years) | 54 (42–65) | 56 (44–66) | 0.12 |
| Male | 324 (52.6) | 122 (65.2) | 0.003 |
| Weight (kg) | 81.5 (69.9–95.3) | 84.8 (72.6–107.9) | < 0.001 |
| BMI (kg/m2) | 29.3 (25.4–33.9) | 31.1 (26.6–37.3) | 0.006 |
| Laboratory values | |||
| CrCl (mL/min) | 98.4 (68.7–127.3) | 83.1 (54.2–115.2) | < 0.001 |
| Serum creatinine (g/dL) | 0.81 (0.66–1.01) | 0.99 (0.76–1.29) | < 0.001 |
| Hemoglobin (g/dL) | 14.1 (12.7–15.2) | 13.9 (12.5–15.2) | 0.52 |
| Platelets (109/L) | 206 (164–266) | 199 (158–250) | 0.13 |
| D-dimer (ng/mL FEU) | 790 (513–1398) | 1540 (760–2500) | < 0.001 |
| D-dimer ≥ 1500 ng/mL FEU on admission | 141 (23.0) | 89 (51.7) | < 0.001 |
| Max amplitude (mm) | 71.7 (69.0–77.1) | 63.9 (50.5–70.9) | 0.03 |
| Comorbidities | |||
| Active cancer | 27 (4.4) | 14 (7.5) | 0.13 |
| Previous VTE | 15 (2.4) | 5 (2.7) | 0.79 |
| Atrial fibrillation | 5 (0.8) | 2 (1.1) | 0.67 |
| ASCVD | 53 (8.6) | 19 (10.2) | 0.56 |
| Known thrombophilia | 5 (0.8) | 4 (2.1) | 0.22 |
| Trauma/surgery | 6 (1.0) | 7 (3.7) | 0.02 |
| Hypertension | 245 (39.8) | 89 (47.6) | 0.06 |
| Chronic kidney disease | 20 (3.3) | 19 (10.2) | < 0.001 |
| Diabetes | 199 (32.3) | 64 (34.2) | 0.66 |
| COPD | 25 (4.1) | 8 (4.3) | 0.84 |
| Asthma | 77 (12.5) | 25 (13.4) | 0.80 |
| Pulmonary hypertension | 8 (1.3) | 2 (1.1) | 0.99 |
| Obstructive sleep apnea | 30 (4.9) | 21 (11.2) | 0.003 |
| Other chronic lung disease | 13 (2.1) | 3 (1.6) | 0.99 |
| In-hospital problems | |||
| Acute kidney injury | 217 (35.2) | 112 (59.9) | < 0.001 |
| Renal replacement therapy | 27 (4.4) | 18 (9.6) | 0.01 |
| P:F ratio | 108 (81–136) | 100 (80–148) | 0.74 |
| Mechanical ventilation | 87 (14.1) | 75 (40.1) | < 0.001 |
| Requiring pressors | 90 (14.8) | 71 (38.0) | < 0.001 |
| Room air | 51 (8.3) | 16 (8.6) | 0.88 |
| Supplemental oxygen | 379 (61.5) | 74 (39.6) | < 0.001 |
| NIV or high-flow nasal cannula | 82 (13.3) | 18 (9.6) | 0.21 |
| Prophylactic initiation regimen | |||
| Enoxaparin 40 mg daily | 359 (58.3) | 87 (46.5) | 0.006 |
| Enoxaparin 30 mg BID | 162 (26.3) | 17 (9.1) | < 0.001 |
| Enoxaparin 40 mg BID | 54 (8.8) | 14 (7.5) | 0.65 |
| Enoxaparin 0.5 mg/kg BID | 3 (0.5) | 1 (0.5) | 0.99 |
| UFH 5000 units TID | 20 (3.3) | 41 (21.9) | < 0.001 |
| UFH 7500 units TID | 18 (2.9) | 8 (4.3) | 0.35 |
| Enoxaparin 30 mg daily | 0 (0) | 1 (0.5) | 0.23 |
| UFH 5000 units BID | 0 (0) | 15 (8.0) | < 0.001 |
| Dalteparin 5000 units daily | 0 (0) | 2 (1.1) | 0.05 |
| UFH 10,000 units TID | 0 (0) | 1 (0.5) | 0.23 |
| Anti-platelets | |||
| Aspirin | 90 (14.8) | 33 (17.7) | 0.35 |
| P2Y12 inhibitor | 13 (2.1) | 5 (2.7) | 0.58 |
| DAPT | 11 (1.8) | 4 (2.1) | 0.76 |
| Admission | |||
| Admitted to ward | 487 (79.0) | 116 (62.0) | < 0.001 |
| Admitted to ICU | 129 (21.0) | 71 (38.0) | < 0.001 |
| Admitted or transferred to ICU | 231 (37.5) | 107 (57.2) | < 0.001 |
| Length of stay | 5 (3–10) | 8 (4–20) | < 0.001 |
| Admitted before protocol | 128 (20.8) | 114 (61.0) | < 0.001 |
| Admitted after protocol | 488 (79.2) | 73 (39.0) | < 0.001 |
All continuous data presented as median (IQR) and all nominal data presented as n (%)
BMI body mass index; CrCl creatinine clearance; FEU fibrinogen equivalent unit; VTE venous thromboembolism; ASCVD atherosclerotic cardiovascular disease; COPD chronic obstructive pulmonary disease; P:F PaO2 to FiO2 ratio; NIV non-invasive ventilation; BID twice daily; TID three times daily; DAPT dual antiplatelet therapy