Background Individual studies have reported widely variable rates for venous thromboembolism (VTE) and bleeding among hospitalized patients with coronavirus disease 2019 (COVID-19). Research question What is the incidence of VTE and bleeding among hospitalized patients with COVID-19? Methods In this systematic review and meta-analysis we searched 15 standard and COVID-19 specific sources between January 1, 2020 and July 31, 2020, with no restriction by language. We pooled incidence estimates using random-effects meta-analyses. We evaluated heterogeneity using the I2 statistic. We assessed publication bias using Begg's and Egger's tests. Results The pooled incidence was 17.0% (95% confidence interval [CI], 13.4%-20.9%) for VTE, 12.1% (95% CI, 8.4%-16.4%) for DVT, 7.1% (95% CI, 5.3%-9.1%) for PE, 7.8% (95% CI, 2.6%-15.3%) for bleeding, and 3.9% (95% CI, 1.2%-7.9%) for major bleeding. In subgroup meta-analyses, the incidence of VTE was higher when assessed by screening (33.1% vs. 9.8% by clinical diagnosis), among patients in the ICU (27.9% vs. 7.1% in the ward), in prospective studies (25.5% vs. 12.4% in retrospective studies), and with the inclusion of catheter-associated thrombosis/isolated distal DVTs and isolated subsegmental PEs. The highest pooled incidence estimate of bleeding was reported for patients receiving intermediate- or full-dose anticoagulation (21.4%) and the lowest in the only prospective study that assessed bleeding events (2.7%). Interpretation Among hospitalized patients with COVID-19, the overall estimated pooled incidence of VTE was 17.0%, with higher rates with routine screening, inclusion of distal DVT and subsegmental PE, in critically ill patients, and in prospective studies. Bleeding events were observed in 7.8% of patients and were sensitive to use of escalated doses of anticoagulants, and nature of data collection. Additional studies are required to ascertain the significance of various thrombotic events and to identify strategies to improve patient outcomes.
Incidence of venous thromboembolism and bleeding among hospitalized patients with COVID-19: a systematic review and meta-analysis