Comparative effectiveness of dabigatran, rivaroxaban, apixaban, and warfarin in the management of patients with nonvalvular atrial fibrillation

Cost-Effectiveness and Budget Impact Analysis of Apixaban and Rivaroxaban Versus Warfarin in the Prevention of Stroke in Patients With Non-Valvular Atrial Fibrillation (NVAF) in Iran

INTRODUCTION

This study evaluates the cost-effectiveness of Apixaban and Rivaroxaban, compared to Warfarin, for stroke prevention in patients with non-valvular atrial fibrillation in Iran.

METHOD

A Markov model with a 30-year time horizon was employed to simulate and assess different treatment strategies' cost-effectiveness. The study population comprised Iranian adults with NVAF, identified through specialist consultations, hospital visits, and archival record reviews. Direct medical costs, direct nonmedical, and indirect costs were included. Quality-adjusted life years (QALY) were assessed using an EQ-5D questionnaire. This study utilized a cost-effectiveness threshold of $11 134 per QALY.

RESULTS

Apixaban demonstrated superior cost-effectiveness compared to Rivaroxaban and Warfarin. Over 30 years, total costs were lower in the Apixaban and Rivaroxaban groups compared to the Warfarin group ($126.18 and $109.99 vs. $150.49). However, Apixaban showed higher total QALYs gained compared to others (0.134 vs. 0.133 and 0.116). The incremental cost-effectiveness ratio for comparing Apixaban to Warfarin was calculated at -1332.83 cost per QALY, below the threshold of $11 134, indicating Apixaban's cost-effectiveness. Sensitivity analyses confirmed the robustness of the findings, with ICER consistently remaining below the threshold. Over 5 years (2024-2028) of Apixaban usage, the incremental cost starts at USD 70 250 296 in the first year and gradually rises to USD 71 770 662 in the fifth year. DSA and PSA were assessed to prove the robustness of the results.

CONCLUSION

This study shows that Apixaban is a cost-effective option for stroke prevention in non-valvular atrial fibrillation patients in Iran compared to Warfarin.

Impact of comparative effectiveness research on Medicare coverage of direct oral anticoagulants

Aim: To evaluate the association of comparative effectiveness research with Medicare coverage of direct oral anticoagulants. Materials & methods: A literature review for direct oral anticoagulants was conducted from 2011 to 2017. Monthly prescription drug plan and formulary files (n = 28) were used to conduct change-point analysis and assess each outcome variable. Results: Up to 2013, studies showed that dabigatran was more effective than rivaroxaban. In 2015, apixaban was shown to be the safest and most effective drug in comparison with all direct oral anticoagulants. In 2016-2017, dabigatran and apixaban were shown to have similar efficacy. Approximately 75% of plans covered dabigatran under tier 3 until 2015. From 2011 to 2017, less than 30% of plans required prior authorizations, 50% imposed quantity limits and mean copayment was lowest for rivaroxaban. Conclusion: Consistent with comparative effectiveness research, Medicare plans covered apixaban more favorably and edoxaban less favorably. However, discrepancies in comparative effectiveness research translation were found for rivaroxaban and dabigatran.

Economic evaluation of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) for stroke prevention in patients with atrial fibrillation: a systematic review and meta-analysis

OBJECTIVES

To assess cost-effectiveness of direct oral anticoagulants (DOACs) compared with vitamin K antagonists (VKAs) for stroke prevention in atrial fibrillation (AF) by pooling incremental net benefits (INBs).

DESIGN

Systematic review and meta-analysis.

SETTING

We searched PubMed, Scopus and Centre for Evaluation of Value and Risks in Health Registry from inception to December 2019.

PARTICIPANTS

Patients with AF.

MAIN OUTCOME MEASURES

The INB was defined as a difference of incremental effectiveness multiplied by willing to pay threshold minus the incremental cost; a positive INB indicated favour treatment. These INBs were pooled (stratified by level of country income, perspective, time-horizon, model types) with a random-effects model if heterogeneity existed, otherwise a fixed effects model was applied. Heterogeneity was assessed using Q test and I² statistic. Risk of bias was assessed using the economic evaluations bias (ECOBIAS) checklist.

RESULTS

A total of 100 eligible economic evaluation studies (224 comparisons) were included. For high-income countries (HICs) from a third-party payer (TPP) perspective, the pooled INBs for DOAC versus VKA pairs were significantly cost-effective with INBs (95% CI) of $6632 ($2961.67 to $10 303.72; I²=59.9%), $6353.24 ($4076.03 to $8630.45; I²=0%), $7664.58 ($2979.79 to $12 349.37; I²=0%) and $8573.07 ($1877.05 to $15 269.09; I²=0%) for dabigatran, apixaban, rivaroxaban and edoxaban relative to VKA, respectively but only dabigatran was significantly cost-effective from societal perspective (SP) with an INB of $11 746.96 ($2429.34 to $21 064.59; I²=52.4%). The pooled INBs of all comparisons for upper-middle income countries (UMICs) were not significantly cost-effective. The ECOBIAS checklist indicated that risk of bias was mostly low for most items with the exception of five items which should be less influenced on pooling INBs.

CONCLUSIONS

Our meta-analysis provides comprehensive economic evidence that allows policy makers to generalise cost-effectiveness data to their local context. All DOACs may be cost-effective compared with VKA in HICs with TPP perspective. The pooling results produced moderate to high heterogeneity particularly in UMICs. Further studies are required to inform UMICs with SP.

PROSPERO REGISTERATION NUMBER

CRD 42019146610.

Choice of oral anticoagulant prescribed by general practices in Wales: Application of Dirichlet regression and linked data

Aims

There has been sustained growth in the prescribing of direct oral anticoagulants (OACs) in primary care in the UK. Given the different indications, properties and prices of OACs, variation between prescribers is expected; however, a high level of variation may be evidence of inappropriate or suboptimal prescribing. This study examined the variation in the relative use of OACs in primary care in Wales.

Methods

Data on total defined daily doses of all community‐dispensed OACs in 2019 were linked at the GP practice level with disease registers, patient demographic data and GP and patient numbers. The relative use of each OAC, as a fraction of all OACs prescribed, was analysed using Dirichlet regression to quantify the association between prescribing patterns and practice and area‐level characteristics.

Results

Across 417 GP practices, the mean (range) in the relative prescribing of warfarin was 37% (6%–64%), apixaban was 32% (2%–65%), rivaroxaban 23% (0%–66%), dabigatran 3% (0%–23%) and edoxaban 6% (0%–59%). Statistical modelling provided strong evidence that prescribing patterns are associated with a GP practice's health board and also their nearest major hospital. Compared to the null model, a model including health board resulted in a 15% fall in Akaike information criterion, increasing to 20% with the addition of nearest major hospital and 27% including further covariates.

Conclusion

Systematic variation in OAC prescribing, by health board and based on nearest hospital, indicates that factors other than patient clinical characteristics and preferences may be influencing prescribing decisions.

Direct-Acting Oral Anticoagulants and Their Reversal Agents-An Update

Background: Over the last ten years, a new class of drugs, known as the direct-acting oral anticoagulants (DOACs), have emerged at the forefront of anticoagulation therapy. Like the older generation anticoagulants, DOACs require specific reversal agents in cases of life-threatening bleeding or the need for high-risk surgery. Methods: Published literature was searched, and information extracted to provide an update on DOACS and their reversal agents. Results: The DOACs include the direct thrombin inhibitor—dabigatran, and the factor Xa inhibitors—rivaroxaban, apixaban, edoxaban, and betrixaban. These DOACs all have a rapid onset of action and each has a predictable therapeutic response requiring no monitoring, unlike the older anticoagulants, such as warfarin. Two reversal agents have been approved within the last five years: idarucizumab for the reversal of dabigatran, and andexanet alfa for the reversal of rivaroxaban and apixaban. Additionally, ciraparantag, a potential “universal” reversal agent, is currently under clinical development. Conclusions: A new generation of anticoagulants, the DOACs, and their reversal agents, are gaining prominence in clinical practice, having demonstrated superior efficacy and safety profiles. They are poised to replace traditional anticoagulants including warfarin.

Cost-effectiveness of edoxaban versus rivaroxaban for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in the US

BACKGROUND

Understanding the value of new anticoagulation therapies compared with existing therapies is of paramount importance in today's cost-conscious and efficiency-driven health care environment. Edoxaban and rivaroxaban for stroke prevention in nonvalvular atrial fibrillation (NVAF) patients with CHADS2 scores ≥2 have been evaluated in pivotal trials versus warfarin. The relative value of edoxaban versus rivaroxaban would be of interest to health care stakeholders and patients who prefer a once-daily treatment option for long-term stroke prevention in NVAF.

OBJECTIVE

To evaluate the relative cost-effectiveness of two once-daily regimens of novel oral anticoagulation therapy - edoxaban (60 mg/30 mg dose-reduced) versus rivaroxaban (20 mg/15 mg dose-reduced) - for stroke prevention in NVAF patients from a US health-plan perspective.

MATERIALS AND METHODS

A Markov model simulated lifetime risk and treatment of stroke, systemic embolism, major bleeding, clinically relevant nonmajor bleeding, myocardial infarction, and death in NVAF patients treated with edoxaban or rivaroxaban. Efficacy and safety data were derived from a network meta-analysis that utilized data from patients enrolled in ENGAGE AF-TIMI 48 and ROCKET-AF. Health care cost and utility data were obtained from published sources. Incremental cost-effectiveness ratios of $150,000 per quality-adjusted life year (QALY) gained were used as thresholds for "highly cost-effective", "cost-effective", and "not cost-effective" treatment options, respectively, as per American Heart Association/American College of Cardiology guidelines.

RESULTS

Edoxaban was dominant relative to rivaroxaban, such that it was associated with lower total health care costs and better effectiveness in terms of QALYs in the base-case analysis. Results were supported by probabilistic sensitivity analyses that showed edoxaban as either dominant or a highly cost-effective alternative (incremental cost-effectiveness ratio <$50,000) to rivaroxaban in 88.4% of 10,000 simulations.

CONCLUSION

Results of this study showed that the once-daily edoxaban (60 mg/30 mg dose-reduced) regimen is a cost-saving or highly cost-effective treatment relative to rivaroxaban (20 mg/15 mg dose-reduced) for stroke prevention in NVAF patients with CHADS2 ≥2.

Adherence to oral anticoagulants in patients with atrial fibrillation-a population-based retrospective cohort study linking health information systems in the Valencia region, Spain: a study protocol

INTRODUCTION

Adherence to oral anticoagulation (OAC) treatment, vitamin K antagonists or new oral anticoagulants, is an essential element for effectiveness. Information on adherence to OAC in atrial fibrillation (AF) and the impact of adherence on clinical outcomes using real-world data barely exists. We aim to describe the patterns of adherence to OAC over time in patients with AF, estimate the associated factors and their impact on clinical events, and assess the same issues with conventional measures of primary and secondary adherence-proportion of days covered (PDC) and persistence-in routine clinical practice.

METHODS AND ANALYSIS

This is a population-based retrospective cohort study including all patients with AF treated with OAC from 2010 to date in Valencia, Spain; data will be obtained from diverse electronic records of the Valencia Health Agency.

PRIMARY OUTCOME MEASURE

adherence trajectories.

SECONDARY OUTCOMES

(1) primary non-adherence; (2) secondary adherence: (a) PDC, (b) persistence. Clinical outcomes: hospitalisation for haemorrhagic or thromboembolic events and death during follow-up.

ANALYSIS

(1) description of baseline characteristics, adherence patterns (trajectory models or latent class growth analysis models) and conventional adherence measures; (2) logistic or Cox multivariate regression models, to assess the associations between adherence measures and the covariates, and logistic multinomial regression models, to identify characteristics associated with each trajectory; (3) Cox proportional hazard models, to assess the relationship between adherence and clinical outcomes, with propensity score adjustment applied to further control for potential confounders; (4) to estimate the importance of different healthcare levels in the variations of adherence, logistic or Cox multilevel regression models.

ETHICS AND DISSEMINATION

This study has been approved by the corresponding Clinical Research Ethics Committee. We plan to disseminate the project's findings through peer-reviewed publications and presentations at relevant health conferences. Policy reports will also be prepared in order to promote the translation of our findings into policy and clinical practice.

Novel oral anticoagulants in non-valvular atrial fibrillation

Atrial fibrillation is the most frequent arrhythmia in clinical practice, reaching 2% of the people in the world and is associated with systemic embolism. Thus, the use of anticoagulants is indicated if CHA2DS2-VASc score ≥ 2 or in patients with previous transient ischemic attack or stroke. For decades, warfarin, a vitamin K antagonist, was the only choice for chronic oral anticoagulation. Recently, novel oral anticoagulants (NOACs) have been introduced, offering similar (or better) effectiveness, safety, and convenience to the vitamin K antagonists. Dabigatran was the first NOAC approved and is a direct thrombin inhibitor. Rivaroxaban and apixaban are factor Xa inhibitors. They display rapid onset of action, more predictable of pharmacological profile, less interactions with other drugs, lack of significant effects in the diet, and less risk of intracranial hemorrhage than warfarin. Despite that dose adjustment is necessary for patients with chronic kidney disease or according to body weight, these new drugs do not require regular monitoring. There are recommendations for the start and follow-up therapy with NOACs, planning for cardioversion, ablation and surgical interventions and the management of bleeding. This article is a review of the major studies of the NOACs. The clinical use of these drugs in patients with non-valvular atrial fibrillation is presented.

A Health Economic Evaluation of Stroke Prevention in Atrial Fibrillation: Guideline Adherence Versus the Observed Treatment Strategy Prior to 2012 in Denmark

BACKGROUND

In 2012 the European Society of Cardiology (ESC) published new guidelines on pharmacological stroke prophylaxis in non-valvular atrial fibrillation (AF). The health economics of adhering to these guidelines in clinical practice remains to be elucidated.

OBJECTIVE

This paper offers a health economic evaluation of two stroke-prophylactic treatment strategies: complete national adherence to the ESC guidelines on stroke prophylaxis in AF versus stroke-prophylactic treatment prior to 2012 in Denmark.

METHODS

A cost-utility analysis was performed to compare two treatment strategies. The first strategy reflected national guideline adherence with the use of non-vitamin K antagonist oral anticoagulants (i.e. dabigatran etexilate), warfarin, and no treatment. The second strategy reflected observed stroke prophylaxis prior to 2012 with the utilization of warfarin, acetylsalicylic acid, and no treatment. A Danish health sector perspective was adopted. A Markov model was designed and populated with information on input parameters from the literature and local cost data reflecting 2014 values. A modeled patient cohort was constructed with a risk profile intended to reflect that of the Danish patient population with AF. The applied outcome was quality-adjusted life-years (QALYs).

RESULTS

The incremental cost-effectiveness ratio amounted to <euro>3557 per QALY for the guideline-adherent treatment strategy (GTS) compared with the pre-2012 treatment strategy. This ratio is below a threshold of <euro>25,000 (£20,000) per QALY. Sensitivity analyses revealed that the result was largely robust to changes in input parameters. All analyses found the GTS to be cost effective.

CONCLUSIONS

Guideline adherence is a cost-effective treatment strategy compared with the strategy employed prior to 2012 for pharmacological stroke prophylaxis in AF.

Quantifying the utility of taking pills for preventing adverse health outcomes: a cross-sectional survey

OBJECTIVES

The utility value attributed to taking pills for prevention can have a major effect on the cost-effectiveness of interventions, but few published studies have systematically quantified this value. We sought to quantify the utility value of taking pills used for prevention of cardiovascular disease (CVD).

DESIGN

Cross-sectional survey.

SETTING

Central North Carolina.

PARTICIPANTS

708 healthcare employees aged 18 years and older.

PRIMARY AND SECONDARY OUTCOMES

Utility values for taking 1 pill/day, assessed using time trade-off, modified standard gamble and willingness-to-pay methods.

RESULTS

Mean age of respondents was 43 years (19-74). The majority of the respondents were female (83%) and Caucasian (80%). Most (80%) took at least 2 pills/day. Mean utility values for taking 1 pill/day using the time trade-off method were: 0.9972 (95% CI 0.9962 to 0.9980). Values derived from the standard gamble and willingness-to-pay methods were 0.9967 (0.9954 to 0.9979) and 0.9989 (95% CI 0.9986 to 0.9991), respectively. Utility values varied little across characteristics such as age, sex, race, education level or number of pills taken per day.

CONCLUSIONS

The utility value of taking pills daily in order to prevent an adverse CVD health outcome is approximately 0.997.

Stroke prevention in patients with atrial fibrillation in France: comparative cost-effectiveness of new oral anticoagulants (apixaban, dabigatran, and rivaroxaban), warfarin, and aspirin

OBJECTIVES

To conduct an economic evaluation of the currently prescribed treatments for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) including warfarin, aspirin, and novel oral anticoagulants (NOACs) from a French payer perspective.

METHODS

A previously published Markov model was adapted in accordance to the new French guidelines of the Commission for Economic Evaluation and Public Health (CEESP), to adopt the recommended efficiency frontier approach. A cohort of patients with NVAF eligible for stroke preventive treatment was simulated over lifetime. Clinical events modeled included strokes, systemic embolism, intracranial hemorrhage, other major bleeds, clinically relevant non-major bleeds, and myocardial infarction. Efficacy and bleeding data for warfarin, apixaban, and aspirin were obtained from ARISTOTLE and AVERROES trials, whilst efficacy data for other NOACs were from published indirect comparisons. Acute medical costs were obtained from a dedicated analysis of the French national hospitalization database (PMSI). Long-term medical costs and utility data were derived from the literature. Univariate and probabilistic sensitivity analyses were performed to assess the robustness of the model projections.

RESULTS

Warfarin and apixaban were the two optimal treatment choices, as the other five treatment strategies including aspirin, dabigatran 110 mg, dabigatran in sequential dosages, dabigatran 150 mg, and rivaroxaban were strictly dominated on the efficiency frontier. Further, apixaban was a cost-effective alternative vs warfarin with an incremental cost of €2314 and an incremental quality-adjusted life year (QALY) of 0.189, corresponding to an incremental cost-effectiveness ratio (ICER) of €12,227/QALY.

CONCLUSIONS

Apixaban may be the most economically efficient alternative to warfarin in NVAF patients eligible for stroke prevention in France. All other strategies were dominated, yielding apixaban as a less costly yet more effective treatment alternative. As formally requested by the CEESP, these results need to be verified in a French clinical setting using stroke reduction and bleeding safety observed in real-life patient cohorts using these anticoagulants.

Validity of standard gamble estimated quality of life in acute venous thrombosis

INTRODUCTION

The standard gamble is considered the 'gold standard' technique for measuring quality of life. We recently used the standard gamble to estimate quality of life in acute venous thrombosis, and found unexpected variability in the responses. The current study aimed to explore the reasons for variability by comparing the standard gamble technique in patients with acute venous thrombosis to other quality of life measurement tools.

MATERIALS AND METHODS

Thrombosis clinic patients treated for venous thrombosis were eligible to participate. Patients evaluated their current health state by performing a standard gamble interview, reporting on a visual analogue scale, completing the SF-36 and disease specific questionnaires (PEmb-Qol and VEINES-QOL/Sym). Validity was assessed by correlating the standard gamble utilities with the other methods. Test-retest reliability, responsiveness and acceptability were also assessed.

RESULTS

Forty-four patients were interviewed, with 16 attending for a repeat interview. The median standard gamble utility was 0.97 (0.84-1.0), SF-6D 0.64 (0.59 - 0.80) and visual analogue score 70 (60 - 80). Participants with pulmonary embolism had lower standard gamble estimates than those with deep vein thrombosis. There was good discriminant validity in that the standard gamble estimates were not associated with risk taking behavior, negative outlook, sex or education. Test-retest reliability with the standard gamble was moderate and there was evidence of a ceiling effect.

CONCLUSIONS

Standard gamble utilities are higher than other methods of measuring quality of life in venous thrombosis. The choice of utility values adopted in studies will impact on future economic studies.

Cost-effectiveness of apixaban versus other new oral anticoagulants for stroke prevention in atrial fibrillation

BACKGROUND

Apixaban (5 mg BID), dabigatran (available as 150 mg and 110 mg BID in Europe), and rivaroxaban (20 mg once daily) are 3 novel oral anticoagulants (NOACs) currently approved for stroke prevention in patients with atrial fibrillation (AF).

OBJECTIVE

The objective of this study was to evaluate the cost-effectiveness of apixaban against other NOACs from the perspective of the United Kingdom National Health Services.

METHODS

A Markov model was developed to evaluate the pharmacoeconomic impact of apixaban versus other NOACs over a lifetime. Pair-wise indirect treatment comparisons were conducted against other NOACs by using ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation), RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy), and ROCKET-AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) trial results for the following end points: ischemic stroke, hemorrhagic stroke, intracranial hemorrhage, other major bleeds, clinically relevant nonmajor bleeds, myocardial infarction, and treatment discontinuations. Outcomes were life-years, quality-adjusted life years gained, direct health care costs, and incremental cost-effectiveness ratios.

RESULTS

Apixaban was projected to increase life expectancy versus other NOACs, including dabigatran (both doses) and rivaroxaban. A small increase in therapeutic management costs was observed with apixaban due to projected gains in life expectancy and lower discontinuation rates anticipated on apixaban versus other NOACs through lifetime. The estimated incremental cost-effectiveness ratio was £9611, £4497, and £5305 per quality-adjusted life-year gained with apixaban compared with dabigatran 150 mg BID, dabigatran 110 mg BID, and rivaroxaban 20 mg once daily, respectively. Sensitivity analyses indicated that results were robust over a wide range of inputs.

CONCLUSIONS

Although our analysis was limited by the absence of head-to-head trials, based on the indirect comparison data available, our model projects that apixaban may be a cost-effective alternative to dabigatran 150 mg BID, dabigatran 110 mg BID, and rivaroxaban 20 mg once daily for stroke prevention in AF patients from the perspective of the United Kingdom National Health Services.

Use of novel oral anticoagulants for patients with atrial fibrillation: systematic review and clinical implications

Atrial fibrillation (AF), a common arrhythmia, increases the risk of ischemic stroke. Stroke and bleeding scores for patients with AF can help to stratify risk and determine the need for antithrombotic therapy, for which warfarin has been the gold standard. Although highly effective, warfarin has several limitations that can lead to its underuse. Data from randomized, Phase III clinical trials of the novel oral anticoagulants, dabigatran, a direct thrombin inhibitor, and rivaroxaban and apixaban, both factor Xa inhibitors, indicate these drugs are at least noninferior to warfarin for the prevention of stroke and systemic embolism. They are easier to administer, and have an equivalent or lower risk of bleeding versus warfarin. A better understanding of the risks and benefits of the novel oral anticoagulants, and their use in clinical practice, will prepare clinicians to anticipate and address educational and clinical needs of AF patients and their families, and promote evidence-based prescription of appropriate and safe anticoagulation therapy.

Cost-effectiveness of pharmacogenetics-guided warfarin therapy vs. alternative anticoagulation in atrial fibrillation

Pharmacogenetics-guided warfarin dosing is an alternative to standard clinical algorithms and new oral anticoagulants for patients with nonvalvular atrial fibrillation. However, clinical evidence for pharmacogenetics-guided warfarin dosing is limited to intermediary outcomes, and consequently, there is a lack of information on the cost-effectiveness of anticoagulation treatment options. A clinical trial simulation of S-warfarin was used to predict times within therapeutic range for different dosing algorithms. Relative risks of clinical events, obtained from a meta-analysis of trials linking times within therapeutic range with outcomes, served as inputs to an economic analysis. Neither dabigatran nor rivaroxaban were cost-effective options. Along the cost-effectiveness frontier, in relation to clinically dosed warfarin, pharmacogenetics-guided warfarin and apixaban had incremental cost-effectiveness ratios of £13,226 and £20,671 per quality-adjusted life year gained, respectively. On the basis of our simulations, apixaban appears to be the most cost-effective treatment.