Abstract
Direct oral anticoagulants (DOACs; namely, rivaroxaban and apixaban) and warfarin are approved for venous thromboembolism (VTE) treatment. Few direct comparisons exist of DOACs on risk of death among patients with VTE, and for patients with concomitant conditions (eg, kidney disease, liver disease), clinical guidelines are unclear. We evaluated 6-month all-cause mortality by anticoagulant prescribed for primary treatment of VTE. Using data from a 20% sample of Medicare beneficiaries, we created a propensity score-matched analytic data set of 47 860 beneficiaries with noncancer incident VTE. We used Cox regression to estimate adjusted hazard ratios (HRs) of OACs with 6-month mortality, and tested interactions by liver and kidney disease. There were 3422 deaths over 6 months of follow-up. In adjusted models, patients prescribed rivaroxaban (HR = 0.82; 95% CI, 0.76-0.90) had lower mortality rates than those prescribed warfarin. There was no association when comparing apixaban with warfarin (HR = 0.96; 95% CI, 0.87-1.07). In head-to-head comparisons of apixaban and rivaroxaban, the HR was 1.14 (95% CI, 1.01-1.28). Findings were similar among patients with liver and kidney disease. Overall, risk of death was similar by OAC prescribed. Though it is possible residual confounding remained, there was some suggestion of lower risk with rivaroxaban than warfarin. Treatment with DOACs appears safe among patients with VTE who have concomitant kidney or liver disease. This article is part of a Special Collection on Pharmacoepidemiology.