Three RCTs with 7,337 participants (4,057 were treated with apixaban and 3,280 treated with subcutaneous enoxaparin) were included. Duration of drug treatment ranged from 10 to 14 days. All studies were considered to be at low risk of bias: randomised treatment allocation sequences were generated in all trials, blinding was conducted across all trials, outcome measurements were unlikely to be influenced by lack of blinding and the numbers and reasons for withdrawal/drop-out were reported.
Compared with enoxaparin, proximal deep-vein thrombosis was significantly less prominent among participants who received apixaban (OR 0.47, 95% CI 0.27 to 0.82, I2=10.6%). There was no significant reduction in the risk of pulmonary embolism (I2=40.8%).
Apixaban was associated with lower major bleeding rates than enoxaparin (OR 0.55, 95% CI 0.32 to 0.96, I2=0). There were no significant differences between treatments for other safety outcomes (clinically relevant non-major bleeding, raised hepatic transaminase enzyme or bilirubin concentrations and arterial thromboembolic events).
There was no evidence for publication bias.