Effectiveness and safety of extended thromboprophylaxis in post-discharge patients with COVID-19: A systematic review and meta-analysis

Background: The effect of extended thromboprophylaxis in improving the prognosis of adult patients with coronavirus disease 2019 (COVID-19) after discharge remains debatable. This meta-analysis was aimed to determine the advantages and disadvantages of extended thromboprophylaxis in these patients.Methods: Different databases such as PubMed, Embase, Web of Science, and Cochrane Library were systemati-cally searched for studies that evaluated the effects of extended thromboprophylaxis in post-discharge patients with COVID-19 until 13 June 2022. The primary efficacy outcome was defined by the composite outcome of thromboembolism and all-cause mortality, and the safety outcome was defined by bleeding events. The odds ratios (ORs) and 95 % confidence intervals (CIs) of efficacy and safety outcomes were calculated using fixed-or random-effects model. Interaction analysis was performed to assess and compare observational studies and randomised controlled trials (RCTs). A sensitivity analysis was performed after excluding studies of poor quality.Results: Eight studies involving 10,148 patients were included. The results confirmed that extended thrombo-prophylaxis, primarily prophylactic use of anticoagulants for <35 days, was significantly associated with reduced composite outcome in high-risk post-discharge patients with COVID-19 (OR: 0.52; 95 % CI: 0.41-0.67, P = 0.000). Interaction analysis revealed that the effect estimates were consistent between the RCT and observational studies (P interaction = 0.310). Furthermore, extended thromboprophylaxis did not increase the risk of major bleeding events (OR: 1.64; 95 % CI: 0.95-2.82, P = 0.075).Conclusion: In post-discharge patients with COVID-19 at high risk of thromboembolism, extended thrombopro-phylaxis, primarily prophylactic use of anticoagulants for <35 days, can significantly reduce the risk of thrombosis and all-cause mortality without increasing the risk of major bleeding events.Registration: PROSPERO CRD42022339399.