Utilization outcomes of direct oral anticoagulants in Medicare patients

Abstract

ObjectiveTo compare the adherence, persistence, discontinuation and switching rates of direct oral anticoagulants (DOACs) for Medicare patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE). MethodsThis was retrospective observational cohort study design. Medicare Part D claims files were used for the study duration (2015–2018). Inclusion-exclusion criteria were applied to identify the NVAF and VTE sample using dabigatran, rivaroxaban, apixaban, edoxaban and warfarin during the identification period (2016–2017). Outcomes of adherence, persistence, time to non-persistence and time to discontinuation were assessed in those who did not switch the index drug in the follow-up period (365 days from the index date). Switching rates were assessed in those who switched the index drug at least once in the aforementioned follow-up period. Descriptive statistics were conducted for all the outcomes, and comparisons were made using t-tests, chi-square, and ANOVA. Logistic regression was conducted to compare the odds of being adherent and the odds of switching in NVAF and VTE patient cohorts. ResultsOf all the DOACs, patients with NVAF or VTE were most adherent to apixaban (PDC = 76.88). Among all the DOACs, non-persistence and discontinuation rates were highest for warfarin. Majority of the switches were reported from dabigatran to other DOAC and to apixaban from other DOAC. Despite the better utilization outcomes reported for apixaban users, Medicare plans covered rivaroxaban favorably. It was associated with the lowest mean amount paid by the patient (NVAF: $76; VTE: $59), and the highest mean amount paid by the plans (NVAF: $359; VTE: $326). ConclusionMedicare plans need to consider adherence, persistence, discontinuation and switching rates of DOACs to make the coverage decisions.