Anticoagulation outcomes in hospitalized Covid-19 patients: A systematic review and meta-analysis of case-control and cohort studies.

ABSTRACT

BACKGROUND: Coagulopathy and thromboembolic events are common in Covid-19 patients and are poor prognostic factors. Controversy exists regarding the potential of anticoagulation (AC) to reduce mortality and incidence of thromboembolic events in Covid-19 patients. The current systematic review and meta-analysis investigated the association between anticoagulants and mortality in adult hospitalized COVID-19 patients using the available published non-randomized studies. METHODS: Google Scholar, PubMed, Scopus, the Cochrane Library and Clinical Trials.gov were searched for relevant studies. A meta-analysis of adjusted and unadjusted estimates was performed. The relative risk was used as a measure of effect. The random-effects model was used to pool estimates using the generic inverse variance method. RESULTS: Sixteen studies were included in the quantitative data synthesis. Results showed a statistically significant association between AC and mortality (RR = 0.56, 95% CI 0.36; 0.92, p = 0.02). Both therapeutic (Relative risk [RR] = 0.4, 95% CI 0.27; 0.57) and prophylactic AC (RR = 0.54, 95% CI 0.41; 0.71) were associated with lower risk of mortality. Pre-admission AC was not associated with mortality (RR = 0.84, 95% CI 0.49; 1.43, p > 0.05) while prophylactic AC was associated with higher risk of mortality compared to therapeutic AC (RR = 1.58, 95% CI 1.34; 1.87, p < 0.001). CONCLUSION: Findings support the association of AC with mortality in Covid-19 patients. The results, synthesized from mostly low-quality studies, show that prophylactic and therapeutic AC might reduce mortality in Covid-19 patients. Findings suggest that therapeutic doses might be associated with better survival compared to prophylactic doses.