Clinical Question

Do anticoagulants reduce the risk of venous thromboembolism or mortality in people hospitalized with COVID-19?

Evidence-Based Answer

In people hospitalized with COVID-19, the use of anticoagulants reduces all-cause mortality (number needed to treat [NNT] = 9; 95% CI, 7.3 to 13). Using a higher dose of anticoagulants may reduce the risk of pulmonary embolism (PE) compared with a lower dose of the same agent (NNT = 56; 95% CI, 44 to 100). Using a higher dose also increases the risk of major bleeding (number needed to harm [NNH] = 100; 95% CI, 42 to 1,000) and minor bleeding (NNH = 50; 95% CI, 10 to 67).¹ (Strength of Recommendation: B, inconsistent or limited-quality patient-oriented evidence.)

Practice Pointers

All patients with COVID-19 are at risk of thromboembolic complications, including deep venous thrombosis (DVT) and PE, and bleeding complications.² In patients hospitalized with COVID-19, rates of DVT (up to 14.8%) and PE (up to 16.5%) are much higher than rates of DVT and PE in hospitalized patients in the United States (0.15% for DVT and 0.1% for PE).^3,4 Clotting and bleeding complications associated with COVID-19 may be caused by dysregulation of the coagulation cascade in response to viral infection.⁵ The authors of this Cochrane review sought to clarify the benefits and risks of anticoagulation for persons hospitalized with COVID-19.