Table 1. Summary of studies.
| Study | Study design | Population | Outcomes | Intervention | Selected baseline characteristics | Efficacy results | Safety results |
| Rowan et al, 200712 | Single center, prospective, nonrandomized | Bariatric surgery patients | Primary: Percent of patients with anti-Xa levels between 0.18 and 0.44 U/mL | 30 mg SQ every 12 hours |
N = 19 74% female Mean BMI: 48.4 ± 7.1 Mean age: 41.7 years Mean score: 1.0 |
0% after 1st dose; 9.1% after 3rd dose |
N/A |
| 40 mg SQ every 12 hours |
N = 33 82% female Mean BMI: 48.5 ± 8.5 Mean age = 40.8 years Mean score = 0.9 |
30.8% after 1st dose; 41.7% after 3rd dose |
N/A | ||||
| Simone et al, 200813 | Single center, prospective, nonrandomized | Bariatric surgery patients | Primary: Mean anti-Xa levels measured 4 hours after 1st and 3rd dose | 40 mg SQ every 12 hours |
N = 22 87.5% female Mean BMI: 48.8 ± 6.6 Mean age: 40.0 years Mean score: 1.0 |
Mean anti-Xa level: 0.17 U/mL after 1st dose; 0.21 U/mL after 2nd dose |
1 major bleeding event (6.3%) |
| 60 mg SQ every 12 hours |
N = 16 93.7% female Mean BMI: 47.3 ± 6.6 Mean age: 41.0 years Mean score: 0.9 |
Mean anti-Xa level: 0.26 U/mL after 1st dose; 0.43 U/mL after 2nd dose |
0 major bleeding events | ||||
| Borkgren-Okonek et al, 200814 | Single center, prospective, nonrandomized | Bariatric surgery patients | Primary: Percent of patients with anti-Xa levels between 0.18 and 0.44 U/mL measured 4 hours after 3rd dose Secondary: VTE and major bleeding | 40 mg SQ every 12 hours (BMI < 50 kg/m2) |
N = 124 77% female Mean BMI: 44.9 (36-50) Mean age: 44.7 years |
79% in therapeutic range; 21% subtherapeutic; 0% supratherapeutic 1 VTE post operative day 37 |
4 major bleeding events |
| 60 mg SQ every 12 hours (BMI >50 kg/m2) |
N = 99 73% female Mean BMI: 57.4 (51-82) Mean age: 44.3 years |
69% within therapeutic range; 14% subtherapeutic; 17% supratherapeutic |
1 major bleeding event | ||||
| Scholten et al, 200218 | Single center, prospective, nonrandomized | Bariatric surgery patients | Primary: Incidence of VTE Secondary: Major bleeding | 30 mg SQ every 12 hours |
N = 92 79.8% female Mean BMI: 51.7 |
5 VTE events (5.4 %) | 1 major bleeding event |
| 40 mg SQ every 12 hours |
N = 389 84.2% female Mean BMI: 50.3 |
2 VTE events (0.6 %) | 1 major bleeding event | ||||
| Hamad, & Choban, 200519 | Multicenter, retrospective, nonrandomized | Bariatric surgery patients | Primary: Incidence of VTE Secondary: Major bleeding | Variable by center – from 30 mg SQ every 24 hours to 40 mg SQ every 12 hours |
N = 668 86% female Mean BMI: 49.6 ± 8.4 Mean age: 39-47 years |
7 VTE events (1.05%) |
6 major bleeding events (0.9%) |
| Escalante-Tattersfield et al, 200820 | Single center, prospective, nonrandomized | Bariatric surgery patients | Primary: Incidence of DVT Secondary: Major bleeding | 40 mg SQ every 12 hours |
N = 451 73% female Mean BMI: 49 (35-90) Mean age: 44 years |
1 VTE, asymptomatic (0.22%) |
No major bleeding |
| Ludwig et al, 201123 | Single center, retrospective | SICU patients | Primary: Percent of patients with anti-Xa levels between 0.2 and 0.5 U/mL 4 to 6 hours after 3rd or 4th dose | 0.5 mg/kg SQ every 12 hours until SICU discharge |
N = 23 57% female Mean BMI: 46.4 (36-77) Mean age: 45.6 years |
91% within therapeutic range; 9% supratherapeutic 1 DVT (4.3%) |
No major bleeding events |
| Freeman et al, 201224 | Single center, prospective | Hospitalized medically ill patients | Primary: Percent anti-Xa levels (0.2-0.5 U/mL) 4 to 6 hours after dose Secondary: VTE, bleeding | 40 mg SQ once daily |
N = 11 81.8% female Mean BMI: 63.4 ± 11.6 Mean age: 45.5 years Mean CrCl: 84 |
18% within therapeutic range; 82% subtherapeutic No VTEs |
No bleeding events |
| 0.4 mg/kg/day |
N = 9 33.3% female Mean BMI: 60.7 ± 12.4 Mean age: 43.8 years Mean CrCl: 135 |
53% within therapeutic range; 36% subtherapeutic; 11% supratherapeutic No VTEs |
No bleeding events | ||||
| 0.5 mg/kg/day |
N = 11 72.7% female Mean BMI: 61.3 ± 12.2 Mean age: 42.7 years Mean CrCl: 139 |
87% within therapeutic range; 13% subtherapeutic No VTEs |
No bleeding events | ||||
Note: BMI = body mass index (kg/m2); CrCl = creatinine clearance (mL/min); DVT = deep vein thrombosis; SCr = serum creatinine; SICU = surgical intensive care unit; SQ = subcutaneous; VTE = venous thromboembolism.