Cost-Utility Analysis of Dabigatran and Warfarin for Stroke Prevention Among Patients With Nonvalvular Atrial Fibrillation in India

OBJECTIVES

Dabigatran has a better safety profile and requires less monitoring, but is costlier than warfarin. This study evaluated the cost-utility of dabigatran relative to warfarin for preventing stroke in nonvalvular atrial fibrillation (NVAF) in India.

METHODS

A Markov decision analysis model was developed to compare dabigatran (110 or 150 mg twice a day) to warfarin titrated to target prothrombin time in patients with NVAF at high risk of stroke. Model utilities and transition probabilities were based on literature and costs on market prices. Data on out-of-pocket expenses and income lost were taken from a nationally representative survey. We adopted a societal perspective and discounted both costs and outcomes at 3%. Ischemic stroke, intracranial bleed, other major bleeds, and death were outcomes of NVAF. The model projected the costs, life-years, and quality-adjusted life-years (QALYs) for each intervention over a lifetime. We used gross domestic product per capita of India (US dollars [US$]1889) as the cost-effectiveness threshold. Sensitivity analyses were conducted.

RESULTS

Treatment with either dose of dabigatran was associated with gain in life-years and QALYs compared with warfarin. The discounted incremental cost-effectiveness ratios/QALYs for both doses of dabigatran (110 mg US$7519; 150 mg US$6634) were above the cost-effectiveness threshold, and the probability of being cost-effective at this threshold was low. Cost of dabigatran was an important factor in determining incremental cost-effectiveness ratio. Price reduction of 150 mg dose by 49% will make it cost-effective.

CONCLUSIONS

Dabigatran is not cost-effective in the Indian societal context. Reducing the price of dabigatran 150 mg by half will make it cost-effective.

ASH, ABHH, ACHO, Grupo CAHT, Grupo CLAHT, SAH, SBHH, SHU, SOCHIHEM, SOMETH, Sociedad Panameña de Hematología, SPH, and SVH 2021 guidelines for management of venous thromboembolism in Latin America

BACKGROUND

Venous thromboembolism (VTE) is a common disease in Latin American settings. Implementing international guidelinn Aes in Latimerican settings requires additional considerations.

OBJECTIVE

The purpose of our study was to provide evidence-based guidelines about managing VTE for Latin American patients, clinicians, and decision makers.

METHODS

We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE)-ADOLOPMENT method to adapt recommendations from 2 American Society of Hematology (ASH) VTE guidelines (Treatment of VTE and Anticoagulation Therapy). ASH and local hematology societies formed a guideline panel comprised of medical professionals from 10 countries in Latin America. Panelists prioritized 18 questions relevant for the Latin American context. A knowledge synthesis team updated evidence reviews of health effects conducted for the original ASH guidelines and summarized information about factors specific to the Latin American context (ie, values and preferences, resources, accessibility, feasibility, and impact on health equity).

RESULTS

The panel agreed on 17 recommendations. Compared with the original guideline, 4 recommendations changed direction and 1 changed strength.

CONCLUSIONS

This guideline adolopment project highlighted the importance of contextualization of recommendations suggested by the changes to the original recommendations. The panel also identified 2 implementation priorities for the region: expanding the availability of home treatment and increasing the availability of direct oral anticoagulants (DOACs). The guideline panel made a conditional recommendation in favor of home treatment for individuals with deep venous thrombosis and a conditional recommendation for either home or hospital treatment for individuals with pulmonary embolism. In addition, a conditional recommendation was made in favor of DOACs over vitamin K antagonists for several populations.

Comparing total medical expenditure between patients receiving direct oral anticoagulants vs warfarin for the treatment of atrial fibrillation: evidence from VA-Medicare dual enrollees

BACKGROUND: Direct oral anticoagulants (DOACs) are an alternative to warfarin for treatment of atrial fibrillation (AF). Evidence demonstrating the efficacy and safety of DOACs has primarily been from clinical trial settings. The real-world effectiveness of DOACs in specific nontrial populations that differ in age, comorbidity burden, and socioeconomic status is unclear. OBJECTIVE: To compare total downstream medical expenditure between AF patients treated with warfarin and DOACs dually enrolled in the Veterans Affairs (VA) Healthcare System and fee-for-service Medicare. METHODS: This was an exploratory treatment effectiveness study that analyzed VA administrative data and Medicare claims. We examined patients with an incident diagnosis for AF and initiated warfarin or DOAC treatment between 2012 and 2015. The primary outcome was total medical expenditure over 3 years following treatment initiation. To address potential informative censoring, we applied a multipart estimator that extends traditional 2-part models to separate differences between groups due to survival and cost accumulation effects. Inverse probability weighting was applied to address potential treatment selection bias. RESULTS: We identified 31,276 and 17,021 patients receiving warfarin and DOACs, respectively. Mean unadjusted (SD) expenditure was higher for warfarin ($56,265 [$96,666]) compared with DOAC patients ($32,736 [$52,470]). Compared with patients receiving DOACs, adjusted 3-year expenditure was $25,688 (P < 0.001) higher for patients receiving warfarin. CONCLUSIONS: VA patients with AF initiating warfarin incurred markedly higher downstream expenditure compared with similar patients receiving DOACs. The benefits of DOACs found in previous clinical trials were present in this population, suggesting that these DOACs may be the preferred option for treatment of AF in older VA patients. DISCLOSURES: This study was funded by a VA Health Services Research and Development Investigator Initiated Research Award (IIR 15-139). Support for VA/CMS data was provided by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Health Services Research and Development, VA Information Resource Center (Project Numbers SDR 02-237 and 98-004). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs, the University of Washington, Northeastern University, and Boston University. The authors declare no conflicts of interest. This research includes data obtained from the VHA Office of Performance Measurement (17API2), which resides within the Office of Analytics and Performance Integration (API), under the Office of Quality and Patient Safety (QPS; formerly known as RAPID). An oral presentation documenting a subset of the findings from this study was presented at the 2020 AcademyHealth Annual Research Meeting, delivered virtually on July 29, 2020.

Burden of oral anticoagulation in embolic stroke of undetermined source without atrial fibrillation

Objective

Prevention of recurrent stroke in patients with embolic stroke of undetermined source (ESUS) is challenging. The advent of safer anticoagulation in the form of direct oral anticoagulants (DOACs) has prompted exploration of prophylactic anticoagulation for all ESUS patients, rather than anticoagulating just those with documented atrial fibrillation (AF). However, recent trials have failed to demonstrate a clinical benefit, while observing increased bleeding. We modeled the economic impact of anticoagulating ESUS patients without documented AF across multiple geographies.

Methods

CRYSTAL-AF trial data were used to assess ischaemic stroke event rates in ESUS patients confirmed AF-free after long-term monitoring. Anticipated bleeding event rates (including both minor and major bleeds) with aspirin, dabigatran 150 mg, and rivaroxaban 20 mg were sourced from published meta-analyses, whilst a 30% ischaemic stroke reduction for both DOACs was assumed. Cost data for clinical events and pharmaceuticals were collected from the local payer perspective.

Results

Compared with aspirin, dabigatran and rivaroxaban resulted in 17.9 and 29.9 additional bleeding events per 100 patients over a patient’s lifetime, respectively. Despite incorporating into our model the proposed 30% reduction in ischaemic stroke risk, both DOACs were cost-additive over patient lifetime, as the costs of bleeding events and pharmaceuticals outweighed cost savings associated with the reduction in ischaemic strokes. DOACs added £5953–£7018 per patient (UK), €6683–€7368 (Netherlands), €4933–€9378 (Spain), AUD$5353–6539 (Australia) and $26,768–$32,259 (US) of payer cost depending on the agent prescribed. Additionally, in the U.S. patient pharmacy co-payments ranged from $2468–$12,844 depending on agent and patient plan. In all settings, cost-savings could not be demonstrated even when the modelling assumed 100% protection from recurrent ischaemic strokes, due to the very low underlying risk of recurrent ischaemic stroke in this population (1.27 per 100 patient-years).

Conclusions

Anticoagulation of non-AF patients may cause excess bleeds and add substantial costs for uncertain benefits, suggesting a personalised approach to anticoagulation in ESUS patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01967-x.

Inclusion in the World Health Organization Model List of Essential Medicines of Non-Vitamin K Anticoagulants for Treatment of Non-Valvular Atrial Fibrillation: A Step Towards Reducing the Burden of Cardiovascular Morbidity and Mortality

Non-vitamin K antagonist oral anticoagulants (NOACs) represent a paradigm shift in the treatment of non-valvular atrial fibrillation (AF) with major practice guidelines around the world recommending NOACs over vitamin K antagonist oral anticoagulants for initial treatment of AF for stroke prevention. Here we describe the evidence collated and the process followed for the successful inclusion of NOACs into the 21st WHO Model List of Essential Medicines (EML).

Individual NOACs have been reported to be non-inferior or superior to warfarin in preventing stroke and systemic embolism in eligible AF patients with a reduction in the risk of stroke and systemic embolism and a lower risk of major bleeding in patients with non-valvular AF compared with warfarin in both RCTs and real-world data.

The successful inclusion of NOACs in the WHO EML is an important step forward in the global fight against cardiovascular morbidity and mortality, especially in low- and middle-income countries, where the burden of disease is high and limited access to diagnosis and treatment translates into a higher burden of morbidity, mortality, and economic costs.

Cost-effectiveness Evaluations Among the Direct Oral Anticoagulants for the Prevention and Treatment of Venous Thromboembolism: Systematic Review

Venous thromboembolism (VTE) is associated with high recurrence, mortality, and cost burden. Direct oral anticoagulants (DOACs) are currently used for VTE treatment, and they offer more benefits over warfarin, despite being more expensive. There is no consensus on the most cost-effective DOAC agent, especially in VTE. This systematic review aims to summarize the comparative cost-effectiveness studies and their impact among DOACs in the treatment of VTE. Literature systematic review of PubMed, Embase, and EconLit was conducted in February 2018 to identify all cost-effectiveness studies of DOAC for the treatment and prevention of VTE. Two independent investigators systematically collected search results and assessed the quality of the studies. The search identified 7 articles, all of which had dabigatran and rivaroxaban as comparators, 6 of which also included apixaban, and 2 of which also had edoxaban. Results of 3 articles concluded that apixaban is a dominant strategy compared to other DOACs in terms of Incremental Cost-Effectiveness Ratio (ICER) in the treatment and prevention of recurrent VTE. One article compared rivaroxaban and dabigatran, with the latter dominating rivaroxaban in terms of ICER. Compared to other DOACs, 2 articles reported apixaban being associated with highest annual total medical cost avoidance of US$4244 and US$4440 per patient-year (ppy), respectively. One article reported that apixaban had the highest annual total medical cost differences of US$918 ppy compared to other DOACs. This systematic review demonstrates that apixaban is considered a cost-effective strategy for VTE treatment and prevention of recurrent VTE.

Systematic review of societal costs associated with stroke, bleeding and monitoring in atrial fibrillation

Aim: Economic consequences associated with the rise in nonvitamin K antagonist oral anticoagulant use on a societal level remain unclear. Materials & methods: Evidence from the past decade on the societal economic burden associated with stroke, bleeding and international normalized ratio monitoring in atrial fibrillation was collected and summarized through a systematic literature review. Results: There were 14 studies identified that reported indirect costs, which were highest among patients with hemorrhagic stroke and intracranial hemorrhage. The contribution of indirect costs to the total was marginal during acute treatment but substantially increased (30-50%) 2 years after stroke and bleeding events. Conclusion: Limited data were available on societal costs in atrial fibrillation and further research is warranted.

Approaches to Direct Oral Anticoagulant Selection in Practice

Direct oral anticoagulants (DOACs) carry many advantages over warfarin and are now considered first line or an alternative for mnay thromboembolic disorders. With the emergence of 5 DOAC agents to the market as well as the accumulating evidence gathered from head-to-head comparisons between the agents, we attempt to provide direction for clinicians when selecting the most appropriate DOAC agent. Important aspects such as efficacy, safety, cost effectiveness, approved indications, and other drug-related factors will be addressed to highlight the major similarities and diversities among the DOACs. When considering the safety profile of DOACs, evidence points toward apixaban as the safest followed by dabigatran and then rivaroxaban. On the other hand, dabigatran currently has the only approved antidote, idarucizumab. According to the approved DOAC indications, rivaroxaban may be favorable in European countries given its additional indication for secondary prevention of myocardial infarction. Following rivaroxaban, dabigatran and apixaban have the largest number of approved indications and lastly comes edoxaban and then betrixaban. For patients with renal impairment, betrixaban is the safest option, followed by apixaban and edoxaban, then rivaroxaban and lastly dabigatran. When considering DOAC dosing, rivaroxaban, edoxaban, and betrixaban are mainly dosed once daily compared to dabigatran and apixaban, which are dosed twice daily. However, rivaroxaban and betrixaban must be administered with food, which adds another level of complexity to the DOAC dosing. Lastly, taking into consideration drug interactions, dabigatran, edoxaban, and betrixaban have the least amount of interactions compared to apixaban and rivaroxaban. Each DOAC has its own set of features that makes it better suited than others based on the exact clinical situation. Therefore, no conclusion can be drawn to the most superior DOAC based on the aspects discussed in this review.

Would the Use of Edoxaban Be Cost-effective for the Prevention of Stroke and Systemic Embolism in Patients With Nonvalvular Atrial Fibrillation in Spain?

INTRODUCTION AND OBJECTIVES

To assess the cost-effectiveness of edoxaban vs acenocoumarol in the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF) in Spain.

METHODS

Markov model, adapted to the Spanish setting from the perspective of the National Health System, stimulating the progression of a hypothetical cohort of patients with NVAF throughout their lifetime, with different health states: stroke, haemorrhage, and other cardiovascular complications. Efficacy and safety data were obtained from the available clinical evidence (mainly from the phase III ENGAGE AF-TIMI 48 study). The costs of managing NVAF and its complications were obtained from Spanish sources.

RESULTS

Edoxaban use led to 0.34 additional quality-adjusted life years (QALY) compared with acenocoumarol. The incremental cost with edoxaban was 3916€, mainly because of higher pharmacological costs, which were partially offset by lower costs of treatment monitoring and managing NVAF events and complications. The cost per QALY was 11 518€, within the thresholds commonly considered cost-effective in Spain (25 000-30 000 €/QALY). The robustness of the results was confirmed by various sensitivity analyses.

CONCLUSIONS

Edoxaban is a cost-effective alternative to acenocoumarol in the prevention of stroke and systemic embolism in patients with NVAF in Spain.

Economic evaluation of prescribing conventional and newer oral anticoagulants in older adults

INTRODUCTION

Anticoagulants refer to a variety of agents that inhibit one or more steps in the coagulation cascade. Generally, clinical conditions that require the prescribing of an oral anticoagulant increase in frequency with age. However, a major challenge of anticoagulation use among older patients is that this group of patients also experience the highest bleeding risk. To date, economic evaluation of prescribing of anticoagulants that includes the novel or newer oral anticoagulants (NOACs) in older adults has not been conducted and is warranted.

AREAS COVERED

A review of articles that evaluated the cost of prescribing conventional (e.g. vitamin K antagonists) and NOACs (e.g. direct thrombin inhibitors and direct factor Xa inhibitors) in older adults.

EXPERT COMMENTARY

While the use of NOACs significantly increases the cost of the initial treatment for thromboembolic disorders, they are still considered cost-effective relative to warfarin since they offer reduced risk of intracranial haemorrhagic events. The optimum anticoagulation with warfarin can be achieved by providing specialised care; clinics managed by pharmacists have been shown to be cost-effective relative to usual care. There are suggestions that genotyping the CYP2C9 and VKORC1 genes is useful for determining a more appropriate initial dose and thereby increasing the effectiveness and safety of warfarin.

Pharmacological and Non-pharmacological Treatments for Stroke Prevention in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.

Influence of novel oral anticoagulants on anticoagulation care management

Anticoagulation treatment was recently improved by the introduction of novel oral anticoagulants (NOACs). Using a combination of qualitative and quantitative methods, this study explores the effects of the introduction of NOACs on anticoagulation care in Slovenia. Face-to-face interviews with key stakeholders revealed evolvement and challenges of anticoagulation care from different perspectives. Obtained information was further explored through the analysis of nationwide data of drug prescriptions and realization of health care services. Simplified management of anticoagulation treatment with NOACs and their high penetration expanded the capacity of anticoagulation clinics, and consequentially the treated population increased by more than 50 % in the last 5 years. The main challenge concerned the expenditures for medicines, which increased approximately 10 times in just a few years. At the same time, the anticoagulation clinics and their core organisation were not affected, which is not expected to change, since they are vital in delivering high-quality care.

Financial Impact of Direct-Acting Oral Anticoagulants in Medicaid: Budgetary Assessment Based on Number Needed to Treat

BACKGROUND

Faced with rising healthcare costs, state Medicaid programs need short-term, easily calculated budgetary estimates for new drugs, accounting for medical cost offsets due to clinical advantages.

OBJECTIVE

To estimate the budgetary impact of direct-acting oral anticoagulants (DOACs) compared with warfarin, an older, lower-cost vitamin K antagonist, on 12-month Medicaid expenditures for nonvalvular atrial fibrillation (NVAF) using number needed to treat (NNT).

METHOD

Medicaid utilization files, 2009 through second quarter 2015, were used to estimate OAC cost accounting for generic/brand statutory minimum (13/23%) and assumed maximum (13/50%) manufacturer rebates. NNTs were calculated from clinical trial reports to estimate avoided medical events for a hypothetical population of 500,000 enrollees (approximate NVAF prevalence × Medicaid enrollment) under two DOAC market share scenarios: 2015 actual and 50% increase. Medical service costs were based on published sources. Costs were inflation-adjusted (2015 US$).

RESULTS

From 2009-2015, OAC reimbursement per claim increased by 173 and 279% under maximum and minimum rebate scenarios, respectively, while DOAC market share increased from 0 to 21%. Compared with a warfarin-only counterfactual, counts of ischemic strokes, intracranial hemorrhages, and systemic embolisms declined by 36, 280, and 111, respectively; counts of gastrointestinal hemorrhages increased by 794. Avoided events and reduced monitoring, respectively, offset 3-5% and 15-24% of increased drug cost. Net of offsets, DOAC-related cost increases were US$258-US$464 per patient per year (PPPY) in 2015 and US$309-US$579 PPPY after market share increase.

CONCLUSIONS

Avoided medical events offset a small portion of DOAC-related drug cost increase. NNT-based calculations provide a transparent source of budgetary-impact information for new medications.