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.

Estimating the cost-effectiveness and return on investment of the Victorian Cardiac Outcomes Registry in Australia: a minimum threshold analysis

OBJECTIVES

We sought to establish the minimum level of clinical benefit attributable to the Victorian Cardiac Outcomes Registry (VCOR) for the registry to be cost-effective.

DESIGN

A modelled cost-effectiveness study of VCOR was conducted from the Australian healthcare system and societal perspectives.

SETTING

Observed deaths and costs attributed to coronary heart disease (CHD) over a 5-year period (2014-2018) were compared with deaths and costs arising from a hypothetical situation which assumed that VCOR did not exist. Data from the Australian Bureau of Statistics and published sources were used to construct a decision analytic life table model to simulate the follow-up of Victorians aged ≥25 years for 5 years, or until death. The assumed contribution of VCOR to the proportional change in CHD mortality trend observed over the study period was varied to quantify the minimum level of clinical benefits required for the registry to be cost-effective. The marginal costs of VCOR operation and years of life saved (YoLS) were estimated.

PRIMARY OUTCOME MEASURES

The return on investment (ROI) ratio and the incremental cost-effectiveness ratio (ICER).

RESULTS

The minimum proportional change in CHD mortality attributed to VCOR required for the registry to be considered cost-effective was 0.125%. Assuming this clinical benefit, a net return of $A4.30 for every dollar invested in VCOR was estimated (ROI ratio over 5 years: 4.3 (95% CI 3.6 to 5.0)). The ICER estimated for VCOR was $A49 616 (95% CI $A42 228 to $A59 608) per YoLS. Sensitivity analyses found that the model was sensitive to the time horizon assumed and the extent of registry contribution to CHD mortality trends.

CONCLUSIONS

VCOR is likely cost-effective and represents a sound investment for the Victorian healthcare system. Our evaluation highlights the value of clinical quality registries in Australia.

Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation: A Systematic Review of Economic Evaluations

OBJECTIVES

Several studies have evaluated the economic evaluation of a group of medications known as novel oral anticoagulant drugs (NOACs) in recent years. The aim of this study is to review and systematically analyze the cost-utility studies results of warfarin compared with other NOAC drugs in atrial fibrillation patients.

METHODS

A systematic review was performed to identify all studies evaluating the NOAC medications in comparison with warfarin. For this purpose, PubMed, Cochrane Library, ISI Web of Science, and Scopus were searched from 2013 to 2022. Articles were independently screened with inclusion criteria, and full texts were reviewed. First, the Consolidated Health Economic Evaluation Reporting Standards checklist was used to evaluate the quality of the articles. Then, the costs and outcomes of the studies were analyzed, and findings were appraised critically.

RESULTS

A total of 84 costs-per-quality-adjusted life-year (QALY) cases were extracted from the studies in which the share of rivaroxaban, edoxaban, apixaban, and dabigatran were 31%, 13%, 29%, and 27%, respectively. The median cost per QALY of rivaroxaban, edoxaban, apixaban, and dabigatran was 21 910$/QALY, 22 096$/QALY, 17 765$/QALY, and 24 161$/QALY, respectively. Subgroup analysis based on perspective showed that dabigatran had the highest incremental cost-effectiveness ratio (ICER) and edoxaban had the lowest ICER value. Edoxaban and apixaban had the highest and the lowest cost per QALY from an insurance perspective, respectively.

CONCLUSION

Despite the differences and variations in the economic evaluation studies of NOAC drugs, these drugs have shown acceptable cost-effectiveness in developed and developing countries. Among NOAC drugs, apixaban has the lowest ICER and the highest cost-effectiveness.

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.

The cost-effectiveness of radial access percutaneous coronary intervention: A propensity-score matched analysis of Victorian data

Background

Despite evidence of the comparative benefits of transradial access percutaneous coronary intervention (PCI) over transfemoral access, its uptake remains highly varied across Australia. Few studies have explored the implications of the choice of access site during PCI from the perspective of the Australian healthcare setting. We, therefore, performed a cost‐effectiveness analysis of radial versus femoral access PCI.

Methods

Data from the Victorian Cardiac Outcomes Registry (VCOR) were used to inform our economic analyses. Patients treated through either radial or femoral access PCI were propensity score‐matched using the inverse probability weighted (IPW) method, and the incidence of major bleeding and all‐cause mortality in the cohort was used to inform an economic model comprising a hypothetical sample of 1000 patients. Costs and utility data were drawn from published sources. The economic evaluation adopted the perspective of the Australian healthcare system.

Results

Among a cohort of 1000 patients over 1 year, there were 19 fewer deaths, and six fewer episodes of nonfatal major bleeding in the radial group compared to the femoral group. Total cost savings attributed to radial access was AUD $1 214 688. Hence, from a health economic point of view, radial access PCI was dominant over femoral access PCI. Sensitivity analyses supported the robustness of these findings.

Conclusions

Radial access is associated with improved patient outcomes and considerably lower costs relative to femoral access PCI. Our findings support radial access being the preferred approach for PCI across a variety of indications in Australia.

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.

Poor outcomes associated with antithrombotic undertreatment in patients with atrial fibrillation attending Gondar University Hospital: a retrospective cohort study

BACKGROUND

Atrial fibrillation (AF) is a major risk factor for stroke as it increases the incidence of stroke nearly fivefold. Antithrombotic treatment is recommended for the prevention of stroke in AF patients. However, majorly due to fear of risk of bleeding, adherence to recommendations is not observed. The aim of this study was to investigate the impact of antithrombotic undertreatment, on ischemic stroke and/or all-cause mortality in patients with AF.

METHODS

A retrospective cohort study was conducted from January 7, 2017 to April 30 2017 using medical records of patients with AF attending Gondar University Hospital (GUH) between November 2012 and September 2016. Patients receiving appropriate antithrombotic management and those on undertreatment, were followed for development of ischemic stroke and/or all-cause mortality. Kaplan-Meier and a log-rank test was used to plot the survival analysis curve. Cox regression was used to determine the predictors of guideline-adherent antithrombotic therapy.

RESULTS

The final analysis included 159 AF patients with a median age of 60 years. Of these, nearly two third (64.78%) of patients were receiving undertreatment for antithrombotic medications. Upon multivariate analysis, history of ischemic stroke/transient ischemic attack (TIA) was associated with lower incidence of antithrombotic undertreatment. A significant increase (HR: 8.194, 95% CI: 2.911-23.066)] in the incidence of ischemic stroke and/or all-cause mortality was observed in patients with undertreatment. Up-on multivariate analysis, only increased age was associated with a statistically significant increase incidence of ischemic stroke and/or all-cause mortality, while only history of ischemic stroke/TIA was associated with a decrease in the risk of ischemic stroke and/or all-cause mortality.

CONCLUSION

Adherence to antithrombotic guideline recommendations was found to be crucial in reducing the incidence of ischemic stroke and/or all-cause mortality in patients with AF without increasing the risk of bleeding. However, undertreatment to antithrombotic medications was found to be high (64.78%) and was associated with poorer outcomes in terms of ischemic stroke and/or all-cause mortality. Impact on practice: This research highlighted the magnitude of antithrombotic undertreatment and its impact on ischemic stroke and/or all-cause mortality in patients with AF. This article has to alert prescribers to routinely evaluate AF patients' risk for ischemic stroke and provide appropriate interventions based on guideline recommendations.

Clinical and Cost Effectiveness of Apixaban Compared to Aspirin in Patients with Atrial Fibrillation: An Australian Perspective

OBJECTIVE

To determine the clinical and cost effectiveness of apixaban compared to aspirin in the prevention of thromboembolic events for patients with atrial fibrillation for whom vitamin K antagonist (VKA) therapy (warfarin) has been considered unsuitable.

METHODS

A previously published Markov model with yearly cycles was updated. Information from the Apixaban Versus Acetylsalicylic acid to prevent Stroke in Atrial Fibrillation (AVERROES) trial in combination with other population data was used to simulate the costs and effects of apixaban compared to aspirin over 10 years. The model comprised five health states. Costs from an Australian healthcare perspective were estimated from published sources for the year 2015. The main outcome of interest was number needed to treat (NNT), number needed to harm (NNH), the incremental cost-effectiveness ratio (ICER) [cost per quality-adjusted life-year (QALY) gained, and cost per year of life saved (YoLS)]. Costs and benefits were discounted at 5.0 % per annum.

RESULTS

For each patient followed up over 10 years, NNT to prevent one additional event (thromboembolic event, death) for apixaban compared to aspirin was 4.6 and 11.8, respectively. NNH was 35.9 for non-fatal major bleeding. The model predicted that compared to aspirin, apixaban would lead to 0.33 YoLS (discounted) and 0.29 QALYs gained (discounted), at an incremental cost of AUD$1996 (discounted). This resulted in ICERs of AUD$6011 per YoLS and AUD$6929 per QALY gained. In the sensitivity analyses, ICERs were most sensitive to efficacy measures derived from the AVERROES study, and time frame.

CONCLUSION

Compared to aspirin, apixaban is likely to be cost effective in preventing thromboembolic disease among VKA unsuitable patients with atrial fibrillation.

Cost Effectiveness of Apixaban versus Warfarin or Aspirin for Stroke Prevention in Patients with Atrial Fibrillation: A Greek Perspective

BACKGROUND

Strokes attributed to atrial fibrillation (AF) represent a major cause of adult disability and a great burden to society and healthcare systems.

OBJECTIVES

Our objective was to assess the cost effectiveness of apixaban, a direct acting oral anticoagulant (DOAC), versus warfarin or aspirin for patients with AF in the Greek healthcare setting.

METHODS

We used a previously published Markov model to simulate clinical events for patients with AF treated with apixaban, the vitamin K antagonist (VKA) warfarin, or aspirin. Clinical events (ischemic and hemorrhagic stroke, intracranial hemorrhage, other major bleed, clinically relevant non-major bleed, myocardial infarction, and cardiovascular [CV] hospitalizations) were modeled using efficacy data from the ARISTOTLE and AVERROES clinical trials. The cohort's baseline characteristics also sourced from these trials. Among VKA-suitable patients, 64.7% were men with a mean age of 70 years and average CHADS₂ (cardiac failure, hypertension, age, diabetes, stroke₂) score of 2.1, whereas 58.5% of VKA-unsuitable patients were men with a mean age of 70 years and a CHADS₂ score of 2.0. A panel of experts (cardiologists and internists) provided information on the resource use associated with the management of AF. Cost calculations reflect the local clinical setting and a third-party payer perspective (€, discounted at 3%).

RESULTS

Based on a simulation of 1000 VKA-suitable patients over a lifetime horizon, the use of apixaban versus warfarin resulted in 26 fewer strokes and systemic embolisms in total, 65 fewer bleeds, 41 fewer myocardial infarctions, and 29 fewer CV-related deaths, with an incremental cost-effectiveness ratio (ICER) of €14,478/quality-adjusted life-year (QALY). For VKA-unsuitable patients, apixaban versus aspirin resulted in 72 fewer strokes and systemic embolisms and 57 fewer CV-related deaths, with an ICER of €7104/QALY. Sensitivity analyses indicated that results were robust.

CONCLUSIONS

Based on the present analysis, apixaban represents a cost-effective treatment option versus warfarin and aspirin for the prevention of stroke in patients with AF from a Greek healthcare payer perspective over a lifetime horizon.

A Systematic Literature Review on the Cost-Effectiveness of Apixaban for Stroke Prevention in Non-valvular Atrial Fibrillation

INTRODUCTION

Economic evaluations are becoming increasingly important due to limitations in economic resources, the expense of many new treatments, the need to allocate health spending as effectively as possible, and the need to inform decision makers. Based on the data from the apixaban studies (ARISTOTLE and AVERROES), several economic evaluations have been performed in various countries to demonstrate the efficacy of apixaban versus warfarin and aspirin or other new oral anticoagulants (NOACs) for preventing stroke in patients with non-valvular atrial fibrillation (NVAF).The aim of this study was to perform a systematic literature review of published economic evaluations with apixaban in the indication of stroke prevention in patients with NVAF.

METHODS

A search in PubMed, Cochrane Library, Google Scholar, and Index Medicus Español was conducted in June 2015. Inclusion and exclusion criteria were established. The main characteristics were recorded for all relevant articles after being reviewed. In addition, a weighted version of the Drummond's checklist was used to further assess the quality of the selected studies.

RESULTS

After review, 26 cost-effectiveness analyses through Markov models were included; the identified economic evaluations represent different willingness-to-pay (WTP) thresholds, discount rates, medical costs, and healthcare systems. Apixaban was compared with warfarin/acenocoumarol in 7 of them (27%), with warfarin/NOACs in 14 (54%), with aspirin in 2 (8%), and with warfarin/aspirin in 3 (11%). Models were conducted from Europe (69%), USA (23%), Australia (4%), and Latin America (4%). All models reported cost/quality-adjusted life years (QALYs) gained, 92% reported using a payer perspective, and 8% using a societal perspective; the median quality score of the selected studies was 89 (out of 119), with a range of 55-103. In models performed in Europe, incremental cost-effectiveness ratios (ICERs) of apixaban versus warfarin ranged from €5607/QALY to €57,245/QALY, while ICERs versus aspirin ranged from being dominant to €7334/QALY. In models carried out in the USA, ICERs of apixaban versus warfarin ranged from being dominant to $93,063/QALY.

CONCLUSION

Different cost-effectiveness analyses suggest that apixaban is a cost-effective therapeutic option according to the WTP thresholds used in countries where cost-effectiveness analyses, were performed.

FUNDING

BMS and Pfizer.

Cost-Effectiveness of Apixaban versus Warfarin in Chinese Patients with Non-Valvular Atrial Fibrillation: A Real-Life and Modelling Analyses

Objectives

Many of the cost-effectiveness analyses of apixaban against warfarin focused on Western populations but Asian evidence remains less clear. The present study aims to evaluate the cost-effectiveness of apixaban against warfarin in Chinese patients with non-valvular atrial fibrillation (NVAF) from a public institutional perspective in Hong Kong.

Methods

We used a Markov model incorporating 12 health state transitions, and simulated the disease progression of NVAF in 1,000 hypothetical patients treated with apixaban/warfarin. Risks of clinical events were based on the ARISTOTLE trial and were adjusted with local International Normalized Ratio control, defined as the time in therapeutic range. Real-life input for the model, including patients’ demographics and clinical profiles, post-event treatment patterns, and healthcare costs, were determined by a retrospective cohort of 40,569 incident patients retrieved from a Hong Kong-wide electronic medical database. Main outcome measurements included numbers of thromboembolic and bleeding events, life years, quality-adjusted life years (QALYs) and direct healthcare cost. When comparing apixaban and warfarin, treatment with incremental cost-effectiveness ratio (ICER) less than one local GDP per capita (USD 33,534 in 2014) was defined to be cost-effective.

Results

In the lifetime simulation, fewer numbers of events were estimated for the apixaban group, resulting in reduced event-related direct medical costs. The estimated ICER of apixaban was USD 7,057 per QALY at base-case analysis and ranged from USD 1,061 to 14,867 per QALY under the 116 tested scenarios in deterministic sensitivity analysis. While in probabilistic sensitivity analysis, the probability of apixaban being the cost-effective alternative to warfarin was 96% and 98% at a willingness to pay threshold of USD 33,534 and 100,602 per QALY, respectively.

Conclusions

Apixaban is likely to be a cost-effective alternative to warfarin for stroke prophylaxis in Chinese patients with NVAF in Hong Kong.

Prevention, management, and rehabilitation of stroke in low- and middle-income countries

Although stroke incidence in high-income countries (HICs) decreased over the past four decades, it increased dramatically in low- and middle-income countries (LMICs). In this review, we describe the current status of primary prevention, treatment, and management of acute stroke and secondary prevention of and rehabilitation after stroke in LMICs. Although surveillance, screening, and accurate diagnosis are important for stroke prevention, LMICs face challenges in these areas due to lack of resources, awareness, and technical capacity. Maintaining a healthy lifestyle, such as no tobacco use, healthful diet, and physical activity are important strategies for both primary and secondary prevention of stroke. Controlling high blood pressure is also critically important in the general population and in the acute stage of hemorrhagic stroke. Additional primary prevention strategies include community-based education programs, polypill, prevention and management of atrial fibrillation, and digital health technology. For treatment of stroke during the acute stage, specific surgical procedures and medications are recommended, and inpatient stroke care units have been proven to provide high quality care. Patients with a chronic condition like stroke may require lifelong pharmaceutical treatment, lifestyle maintenance and self-management skills, and caregiver and family support, in order to achieve optimal health outcomes. Rehabilitation improves physical, speech, and cognitive functioning of disabled stroke patients. It is expected that home- or community-based services and tele-rehabilitation may hold special promise for stroke patients in LMICs.