Background: Oral anticoagulants (OACs), such as apixaban and warfarin, are indicated for reducing the risk of recurrent venous thromboembolism (VTE) and are often initiated in the hospital. The aim of this study was to evaluate OAC continuity from inpatient to outpatient settings and the risk of recurrent VTE among patients with an initial event. Methods: This retrospective cohort study utilized hospital charge data and medical and prescription claims from 1 July 2016 to 31 December 2022 to identify adults treated with apixaban or warfarin while hospitalized for VTE. Patients were followed to assess switching or discontinuation post-discharge and the risk of recurrent VTE. The index date was the date of the first apixaban or warfarin claim within 30 days post-discharge. Results: Of the 19,303 eligible patients hospitalized with VTE, 85% (n = 16,401) were treated with apixaban and 15% (n = 2902) received warfarin. After discharge, approximately 70% had ≥1 fill for their respective apixaban or warfarin therapy. The cumulative incidence of discontinuation over the 6 months following index was 50.5% and 52.2% for the apixaban and warfarin cohorts, respectively; the cumulative incidence of switching was 6.0% and 20.9%, respectively. The incidence rates of recurrent VTE were 1.2 and 2.5 per 100 person-years for the apixaban and warfarin cohorts, respectively. Conclusions: The majority of patients continued their apixaban or warfarin therapy following hospital discharge; however, a considerable proportion either switched or discontinued OAC upon transitioning from inpatient care. Among those who continued therapy, discontinuation, switch, and recurrent VTE occurred less often with apixaban vs. warfarin.

BACKGROUND: Venous thromboembolism (VTE) is a major public health condition that renders patients at risk of recurrent events, which significantly increases their morbidity, mortality, and health care costs. Apart from warfarin, direct oral anticoagulants, such as apixaban, dabigatran, or rivaroxaban, are approved for VTE treatment. Cardiovascular drugs are largely impacted by formulary restrictions; however, the impact on oral anticoagulants (including warfarin and direct oral anticoagulants) in VTE has not been well studied. OBJECTIVE: To describe the extent of payer-rejected claims for oral anticoagulants for VTE and the factors associated with rejected claims. Prescription abandonment of oral anticoagulants and the time to an eventual fill for oral anticoagulant after rejection or abandonment were also evaluated. METHODS: A retrospective cohort study was conducted among patients with VTE newly prescribed an oral anticoagulant (first claim was the index) between October 2016 and October 2021. Descriptive statistics were used to describe the proportion of patients with paid (ie, filled), rejected, or abandoned index oral anticoagulant prescription and journey to paid prescription among those with initial rejection. Multivariable logistic regression was used to identify factors associated with initial rejection. RESULTS: Among the overall sample (N = 297,312), 74.3% had initial oral anticoagulant prescriptions approved, 9.1% had them rejected, and 16.7% abandoned them. Of the patients with initial rejection, 82.1% eventually filled their oral anticoagulant prescriptions; however, for 14.2% of these patients, the first fill was for an oral anticoagulant other than that initially prescribed. The mean time to a first fill for an oral anticoagulant after an initial rejection was 18.3 days. More than half of the patients with an initial rejected oral anticoagulant claim had at least 1 additional rejection during the follow-up period. Of the patients who abandoned their initial oral anticoagulant prescription, 83.9% filled an oral anticoagulant prescription during follow-up; the mean time to fill for the index oral anticoagulant was 15.6 days. Oral anticoagulant type, Medicare payer coverage, prescribing physician specialty, and VTE diagnosis setting of care were significantly associated with index oral anticoagulant claim rejection ( P <0.05). CONCLUSIONS: Rejection and abandonment may delay access to oral anticoagulant treatment. Factors contributing to these scenarios should be understood and addressed for proper VTE management.

Objective: This study aimed to describe oral anticoagulant (OAC) use among patients with venous thromboembolism (VTE). Materials and methods: This study included Medicare fee-for-service beneficiaries (data from 1/1/2014-12/31/2019) newly diagnosed with VTE. Factors associated with being untreated with OACs in the first month from VTE (vs. OAC-treated), with receiving direct-acting OACs ([DOACs] vs. warfarin), and with extended OAC treatment (>3 months) were assessed using multivariable logistic regressions. Results: Overall, 169,928 patients with VTE (50.3% OAC-untreated) were included. Among the 49.7% OAC-treated patients, 74.0% used DOACs and 62.5% had extended OAC treatment. Factors associated with being untreated with OACs in the first month from VTE (odds ratio; 95% confidence interval) included Hispanic ethnicity (vs. White;1.35; 1.29–1.42), having part D low-income subsidy (1.14; 1.07, 1.20), and comorbidities such as cardiovascular diseases. Among the OAC-treated cohort, patients with index VTE diagnosis in the emergency room (vs. outpatient) setting had higher odds of receiving DOAC vs. warfarin; patients with pulmonary embolism diagnosis (vs. deep vein thrombosis) had higher odds of extended OAC treatment. Conclusions: In this study of Medicare patients newly diagnosed with VTE, half of the patients were not treated with OAC in the first month from initial diagnosis. Factors such as Hispanic ethnicity, having low-income subsidy, and comorbidity burden were found to be associated with being untreated with OAC. Among OAC-treated patients, the majority were treated with DOAC vs. warfarin. Interestingly, more than a third of OAC-treated patients were not treated beyond 3 months, which warrants further investigation.

Background Oral anticoagulants (OACs) are recommended for stroke reduction in non-valvular atrial fibrillation (NVAF). OAC use has been studied in Medicare populations, but data for younger, commercially insured populations are limited. Objective This retrospective study aimed to describe the geographic variation of OAC use among commercially insured patients with NVAF at high risk of stroke (CHA₂DS₂-VASc score ≥ 2) in the USA. Methods Geographic variation was assessed by 3-digit zip code and race among patients identified from the Komodo Health commercial database with a diagnosis of NVAF between January 1, 2016, and August 31, 2021. Continuous health plan enrollment for ≥ 12 months before and 12 months after the NVAF diagnosis was required. Results A total of 619,111 patients with NVAF at high risk for stroke were identified, of whom approximately 50% were not treated with OACs. Of the half who received OACs, almost 85% received direct OACs (DOACs) and 15% received warfarin therapy. Overall, the highest untreated rates were observed in the South and West US regions, followed by the Midwest, then the Northeast. The highest DOAC treatment rates were in the Northeast for White patients and in the North and South for Black patients. The highest warfarin treatment rates were in the upper Midwest for White patients and the Midwest for Black patients. Conclusions This study may help guide the identification of areas to target interventions to improve treatment rates and confirm prior findings of geographic and racial variations of OAC use in NVAF.

Several observational studies have compared apixaban with rivaroxaban in patients with non-valvular atrial fibrillation (NVAF), but these analyses may be confounded by unmeasured characteristics. This study used provider prescribing preference (PPP) as an instrumental variable (IV) to assess the association between prescriber choice of rivaroxaban vs. apixaban and the study outcomes of stroke/systemic embolism (SE), major bleeding, and death in a retrospective cohort of NVAF patients in the US. Initiators of either medication were linked to their prescribers and followed until the first of the study outcome, the end of rivaroxaban/apixaban use, or 365 days after initiation. PPP for each patient was the percent of rivaroxaban initiations issued by the provider for the prior 10 NVAF patients. Cox regression models tested associations between quintiles of PPP and each outcome. A total of 61,155 patients and 1726 providers were included. The IV was a strong predictor of rivaroxaban prescription (OR = 17.9; 95% CI: 16.6, 19.3). There were statistically significant associations between increasing preference for rivaroxaban and rates of major bleeding (ptrend = 0.041) and death (ptrend = 0.031), but not stroke/SE (ptrend = 0.398). This analysis provides evidence of the relative safety of apixaban over rivaroxaban for the risk of major bleeding and death.