Cost-effectiveness of apixaban and warfarin in the prevention of thromboembolic complications among atrial fibrillation patients

Methods for Economic Evaluations of Novel Oral Anticoagulants in Patients with Atrial Fibrillation: A Systematic Review

BACKGROUND

Atrial fibrillation (AF) is a severe epidemiological and public health concern among the elderly population worldwide, with substantial economic and social burdens. Economic evaluations can play an essential role in optimizing the utilization of scarce resources. In recent years, the number of economic evaluation studies related to AF has increased due to the rising number of AF patients, the continuous updating of clinical data, and the emergence of real-world evidence. However, there are still deficiencies in model settings and parameter sources in relevant studies.

OBJECTIVE

This study aims to review the existing economic evaluations of novel oral anticoagulants (NOACs) in patients with AF and summarize the evidence and methods applied.

METHODS

A comprehensive and systematic search was conducted on electronic databases, including PubMed, Embase, Web of Science (WOS), and The Cochrane Library, from the date of database creation to November 2022. The reporting quality of included literature was assessed using the Consolidated Health Economic Evaluation Reporting Standards 2022 (CHEERS 2022) statement.

RESULTS

A total of 102 studies were included in the review, with 200 comparisons between NOACs and vitamin K antagonists (VKAs), as well as 58 comparisons between different NOACs. The healthcare sector and payer perspectives were the most common, and accordingly, the majority of the evaluations considered only direct medical costs. Most studies used Markov cohort models with the number of health states ranging from 4 to 29. Of included studies, 80 (78%) considered event recurrence and complications, and 78 (76%) considered discontinuation and second-line therapy. All of the studies applied uncertainty analysis to explore the robustness of the results. Of all 200 NOACs-VKAs comparisons, 149 (75%) showed that NOACs were more cost-effective; this proportion was 84% (139 out of 165) in high-income countries but decreased to 29% (10 out of 35) in middle- and low-income countries. Most (82%) of the 28 items in the CHEERS 2022 checklist were elucidated in the majority of included studies. A minority (only 39%) of included studies demonstrated high reporting quality.

CONCLUSION

NOACs may be more cost-effective than VKAs in patients with AF, but this conclusion applies to high-income countries, whereas VKAs may be more cost-effective in middle- and low-income countries. The reporting quality of included studies was variable, and certain methodological issues were presented. This study highlights the economic evaluation methodology of NOACs in patients with AF and provides recommendations for modeling methods and future studies.

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.

Cost-Effectiveness of Apixaban versus Other Direct Oral Anticoagulants and Warfarin in the Prevention of Thromboembolic Complications Among Finnish Patients with Non-Valvular Atrial Fibrillation

Purpose

Direct oral anticoagulant (DOAC) use for the prevention of thromboembolic complications in patients with non-valvular atrial fibrillation (AF) has increased steadily in Finland. DOACs have been shown to be cost-effective in comparison to warfarin, but published evidence of relative cost-effectiveness between DOACs is still scarce and mostly based on indirect comparisons of clinical trial evidence. The aim of this study was to compare the cost-effectiveness of apixaban to dabigatran, rivaroxaban and warfarin in a Finnish setting using real-life evidence where available.

Patients and Methods

A lifetime Markov simulation model used previously in a published Finnish assessment comparing apixaban and warfarin was modified and updated with the relative effectiveness and safety data available from the real-world NAXOS-study and representative Finnish input data for patient characteristics, event risks, mortality, resource use, costs, and quality of life. Apixaban’s cost-effectiveness was assessed from health care payer perspective (using 3% per year discount rate) based on incremental cost-effectiveness ratio (ICER, cost per quality-adjusted life year [QALY] gained), probability of cost-effectiveness (at willingness-to-pay [WTP] of 35,000 euros/QALY), and net monetary benefit (NMB).

Results

Apixaban increased the average modelled quality-adjusted life-expectancy and reduced the average total health care costs of AF patients when compared to warfarin (+0.14 QALYs, −3691 euros), dabigatran (+0.11 QALYs, −404 euros), and rivaroxaban (+0.03 QALYs, −43 euros). The resulting NMB of apixaban versus warfarin, dabigatran and rivaroxaban was 8723, 4168, and 1129 euros, respectively. The respective probabilities of apixaban being cost-effective against each comparator were 100%, 92.7%, and 64.0%.

Conclusion

In this modelling study, apixaban dominated other anticoagulants in the Finnish real-life setting.

Cost-utility analysis of heart surgeries for young adults with severe rheumatic mitral valve disease in India

BACKGROUND

Rheumatic mitral valve disease (RMVD) is a major cause of acquired valvular disease in India. We compared the cost-effectiveness of surgical treatment strategies for young adults with severe RMVD from an Indian public payer perspective.

METHODS

We developed a Markov model to reflect the burden of RMVD among a hypothetical cohort of 20-year-olds in India and to estimate quality-adjusted life years (QALYs) and lifetime costs associated with three strategies: (1) Repair; (2) Mechanical valve replacement (MVR-M); and (3) Bioprosthetic valve replacement (MVR-B), compared to a baseline strategy involving a mix of surgeries approximating the standard of care in India (32% Repair, 33% MVR-M, 35% MVR-B). Data on disease burden, intervention effects, and direct medical costs (2018 US$) were obtained from the literature. Deterministic and probabilistic sensitivity analyses were conducted to assess model uncertainty.

RESULTS

Repair ($2530, 9.7 QALYs) was less costly and more effective than the standard of care ($2990, 8.7 QALYs) and MVR-M ($3220, 6.2 QALYs). The incremental cost-effective ratio for MVR-B ($3190, 10.1 QALYs) compared to Repair was $1590 per QALY, which may be cost-effective at a threshold of India's per-capita gross domestic product (GDP: $2005). The optimal choice between Repair or MVR-B was sensitive to variations in surgery costs, background mortality, and risks for reoperation.

CONCLUSIONS

Our model-based analysis suggests that Repair is the optimal strategy and MVR-M should not be recommended for this subpopulation. MVR-B may be cost-effective in contexts where quality of Repair is not assured, newer generation bioprostheses are used, or the costs of the bioprosthetic valve decrease.

Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke: a systematic review and economic evaluation

BACKGROUND

Cryptogenic stroke is a stroke for which no cause is identified after standard diagnostic tests. Long-term implantable cardiac monitors may be better at diagnosing atrial fibrillation and provide an opportunity to reduce the risk of stroke recurrence with anticoagulants.

OBJECTIVES

The objectives were to assess the diagnostic test accuracy, clinical effectiveness and cost-effectiveness of three implantable monitors [BioMonitor 2-AF™ (Biotronik SE & Co. KG, Berlin, Germany), Confirm Rx™ (Abbott Laboratories, Lake Bluff, IL, USA) and Reveal LINQ™ (Medtronic plc, Minneapolis, MN, USA)] in patients who have had a cryptogenic stroke and for whom no atrial fibrillation is detected after 24 hours of external electrocardiographic monitoring.

DATA SOURCES

MEDLINE, EMBASE, The Cochrane Library, Database of Abstracts of Reviews of Effects and Health Technology Assessment databases were searched from inception until September 2018.

REVIEW METHODS

A systematic review was undertaken. Two reviewers agreed on studies for inclusion and performed quality assessment using the Cochrane Risk of Bias 2.0 tool. Results were discussed narratively because there were insufficient data for synthesis. A two-stage de novo economic model was developed: (1) a short-term patient flow model to identify cryptogenic stroke patients who have had atrial fibrillation detected and been prescribed anticoagulation treatment (rather than remaining on antiplatelet treatment) and (2) a long-term Markov model that captured the lifetime costs and benefits of patients on either anticoagulation or antiplatelet treatment.

RESULTS

One randomised controlled trial, Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL-AF) (Sanna T, Diener HC, Passman RS, Di Lazzaro V, Bernstein RA, Morillo CA, et al. Cryptogenic stroke and underlying atrial fibrillation. N Engl J Med 2014;370:2478-86), was identified, and no diagnostic test accuracy study was identified. The CRYSTAL-AF trial compared the Reveal™ XT (a Reveal LINQ predecessor) (Medtronic plc) monitor with standard of care monitoring. Twenty-six single-arm observational studies for the Reveal devices were also identified. The only data for BioMonitor 2-AF or Confirm Rx were from mixed population studies supplied by the companies. Atrial fibrillation detection in the CRYSTAL-AF trial was higher with the Reveal XT than with standard monitoring at all time points. By 36 months, atrial fibrillation was detected in 19% of patients with an implantable cardiac monitor and in 2.3% of patients receiving conventional follow-up. The 26 observational studies demonstrated that, even in a cryptogenic stroke population, atrial fibrillation detection rates are highly variable and most cases are asymptomatic; therefore, they probably would not have been picked up without an implantable cardiac monitor. Device-related adverse events, such as pain and infection, were low in all studies. The de novo economic model produced incremental cost effectiveness ratios comparing implantable cardiac monitors with standard of care monitoring to detect atrial fibrillation in cryptogenic stroke patients based on data for the Reveal XT device, which can be related to Reveal LINQ. The BioMonitor 2-AF and Confirm RX were included in the analysis by making a strong assumption of equivalence with Reveal LINQ. The results indicate that implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold. When each device is compared incrementally, BioMonitor 2-AF dominates Reveal LINQ and Confirm RX.

LIMITATIONS

The cost-effectiveness analysis for implantable cardiac monitors is based on a strong assumption of clinical equivalence and should be interpreted with caution.

CONCLUSIONS

All three implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold, compared with standard of care monitoring, for cryptogenic stroke patients with no atrial fibrillation detected after 24 hours of external electrocardiographic monitoring; however, further clinical studies are required to confirm their efficacy in cryptogenic stroke patients.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018109216.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 5. See the NIHR Journals Library website for further project information.

Cost-Effectiveness of Coronary and Peripheral Artery Disease Antithrombotic Treatments in Finland

Introduction

Currently, 15–20% of individuals with coronary artery disease (chronic coronary syndrome [CCS]) or peripheral artery disease (PAD) receiving routine treatment experience cardiovascular events (CVEs) within 3–4 years. Using PICOSTEPS (Patients-Intervention-Comparators-Outcomes-Setting-Time-Effects-Perspective-Sensitivity analysis) reporting, we evaluated the cost-effectiveness of recently approved rivaroxaban 2.5 mg twice daily in combination with acetylsalicylic acid 100 mg daily (RIV + ASA) for the prevention of CVEs among Finns with CCS or symptomatic PAD.

Methods

Myocardial infarction, ischemic stroke, intracranial hemorrhage, acute limb ischemia, amputations, major extracranial bleeding, venous thromboembolism, and cardiovascular deaths were modeled in a Markov model examining a cohort of patients with CCS or symptomatic PAD. Relative effects of the intervention (RIV + ASA) and comparator (ASA) were based on the COMPASS trial. The primary outcome was 3%/year discounted incremental cost-effectiveness ratio (ICER), defined as cost (2019 euros) per quality-adjusted life year (QALY) gained in the Finnish setting over a lifetime horizon. In addition to nonfatal and fatal CVEs, the effects factored Finnish non-CVE mortality, quality of life, and direct costs from a public payer perspective. Disaggregated costs and QALYs, costs per life year gained (LYG), and ischemic strokes avoided, net monetary benefit (NMB), expected value of perfect information (EVPI), economic value-added (EVA), cost-effectiveness table, and acceptability frontier were examined. Probabilistic and deterministic sensitivity analyses were conducted.

Results

In the deterministic comparison with ASA over a lifetime horizon, RIV + ASA resulted in a benefit of 0.404 QALYs and 0.474 LYGs for an additional cost of €3241, resulting in an ICER of €8031/QALY. The probabilistic ICER was €4313/QALY (EVPI €1829/patient). RIV + ASA had positive NMB (€8791/patient), low EVPI (€88/patient), high EVA (€8703/patient), and 91% probability of cost-effectiveness using the willingness-to-pay of €25,254/QALY. The primary result was conservative and robust for RIV + ASA.

Conclusion

RIV + ASA was a cost-effective treatment alternative compared with ASA in patients with CCS or symptomatic PAD in Finland.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01398-8) contains supplementary material, which is available to authorized users.

Finland lacks published evidence on the cost-effectiveness of approved interventions for the prevention of cardiovascular events among individuals with chronic coronary syndrome (stable coronary artery disease) or symptomatic peripheral artery disease at risk of cardiovascular complications. Rivaroxaban 2.5 mg twice daily plus acetylsalicylic acid 100 mg once daily is indicated and reimbursed in Finland for the prevention of cardiovascular events for patients with stable coronary artery disease or symptomatic peripheral artery disease. We assessed the effectiveness and costs of treatment with rivaroxaban plus acetylsalicylic acid in comparison with treatment with acetylsalicylic acid. That is, we examined whether rivaroxaban is cost-effective when prescribed in combination with acetylsalicylic acid.

Cardiovascular events with their associated costs and impact on quality of life were modeled over the lifetime of patients. The main effectiveness outcome was quality-adjusted life years (modeled survival multiplied by the expected quality of life), and costs included those relevant to the Finnish public payer in 2019. Extensive sensitivity analyses were carried out to evaluate the impacts of different model inputs and rationale.

Rivaroxaban plus acetylsalicylic acid had high probability of being cost-effective, compared with acetylsalicylic acid. By valuing quality-of-life benefit with a plausible willingness-to-pay, net cost savings of €8791 per patient could be gained or economic value added by €8703 per patient if rivaroxaban was used.

Cost-Utility Analysis of Apixaban versus Warfarin in Atrial Fibrillation Patients with Chronic Kidney Disease

BACKGROUND

Warfarin use for stroke prevention in atrial fibrillation (AF) patients with chronic kidney disease is debated. Apixaban was shown to be safer than warfarin, with superior reduction in the risk of stroke, systemic embolism, mortality, and major bleeding irrespective of kidney function.

OBJECTIVES

To evaluate the cost-utility of apixaban compared with warfarin in AF patients at different levels of kidney function.

METHODS

A Markov model was used to estimate the cost effectiveness of apixaban compared with warfarin in AF patients at three levels of kidney function: estimated glomerular filtration rate (eGFR) of more than 80 ml/min, 50 to 80 ml/min, and 50 ml/min or less. Event rates and associated utilities were obtained from previous literature. The model adopted the US health care system perspective, with hospitalization costs extracted from the Healthcare and Utilization Project. Treatment costs were obtained from official price lists. Univariate and probabilistic sensitivity analyses were performed to evaluate the robustness of results.

RESULTS

Apixaban was a dominant treatment strategy compared with warfarin in AF patients with eGFR levels of 50 ml/min or less and 50 to 80 ml/min. In patients with an eGFR of more than 80 ml/min, apixaban was cost-effective compared with warfarin, costing $6307 per quality-adjusted life-year gained. Results were consistent assuming anticoagulant discontinuation after major bleeding events. Compared with dabigatran and rivaroxaban, apixaban was the only cost-effective anticoagulant strategy relative to warfarin in both mild and moderate renal impairment settings.

CONCLUSIONS

Apixaban is a favorably cost-effective alternative to warfarin in AF patients with normal kidney function and potentially cost-saving in those with renal impairment.