Cost Implications of Formulary Decisions on Oral Anticoagulants in Nonvalvular Atrial Fibrillation

Abstract

In the European Union, 4.5 million people are estimated to have AF.2 Patients with untreated AF are at a 4-to 5-fold increased risk of stroke compared with those without the disease. Vitamin K antagonists (VKAs), such as warfarin, have been successfully used for many years to provide prophylaxis against stroke in patients with AF. A large meta-analysis of randomized trials showed that adjusted-dose warfarin reduced the incidence of stroke by 64%. 4 However, in a real-world analysis of Medicare patients with AF, the reduction in stroke with warfarin was lower than in the meta-analysis, at 27%. 5While effective, VKAs are associated with a number of limitations: they have numerous drug and food interactions; their effect is influenced by genetic factors; and they have a narrow therapeutic range, requiring frequent international normalized ratio (INR) monitoring and dose adjustments.6 As a result of these factors, there is considerable variability in the amount of time patients spend within the therapeutic range (INR, 2.0-3.0), which exposes them to stroke when they are below the range and bleeding when they are above the range.New anticoagulants have been developed to reduce the risk of stroke in patients with AF. These oral agents are direct inhibitors of single coagulation factors and include dabigatran, rivaroxaban, and apixaban.7 They meet the need for predictable anticoagulation with fixed dosing, without the need for laboratory monitoring. As may be expected, these anticoagulants are more expensive per unit than warfarin.7 However, the

Targeting stroke risk and improving outcomes in patients with atrial fibrillation in Latin America

“…[19][20][21][22][23] Acquisition costs for these drugs are higher than for warfarin, but a cost-benefit review of treatment for atrial fibrillation, based on observational studies, suggested that the overall cost of therapy may be lower because, in contrast to warfarin, dose adjustment and routine monitoring of the anticoagulant effect are not required, and the risk of complications from therapy over the long term may be lower. 51 However, cost-effectiveness comparisons of non-vitamin K antagonist agents versus warfarin are warranted before the results can be directly applied to the real-world setting. …”

Health Care Resource Utilization, Costs, and Persistence in Patients Newly Diagnosed as Having Nonvalvular Atrial Fibrillation and Newly Treated With Dabigatran versus Warfarin in the United States

“…Both INR testing and the consequences of poor INR control consume considerable health care resources. [11][12][13] Dabigatran, 14 a direct thrombin inhibitor, is an OAC approved by the Food and Drug Administration in the United States in October 2010 to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF), which represents approximately 95% of AF cases. 15 Dabigatran offers several advantages over warfarin.…”

Antithrombotic Usage Patterns in the Era of New Oral Anticoagulant Options for Atrial Fibrillation

“…Alternatively, warfarin has known interpatient variability, and numerous drug, food, and disease interactions requiring frequent laboratory monitoring, which is highly dependent on patient compliance and can increase cost. 10,[26][27][28] In reality, patient compliance may play a significant role in the frequency of laboratory follow-up, leading to an increase in health care costs. Therefore, the new agents are attractive alternatives to warfarin for some patients.…”