Updating the Cost Effectiveness of Oral Anticoagulants for Patients with Atrial Fibrillation Based on Varying Stroke and Bleed Risk Profiles

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.

Cost-Effectiveness Analysis of Direct Oral Anticoagulants Vs. Vitamin K Antagonists in the Elderly With Atrial Fibrillation: Insights From the Evidence in a Real-World Setting

Background: In the clinical setting, the economic benefits of direct oral anticoagulants (DOACs) in elderly patients with atrial fibrillation (AF) remain unclear. This study aimed to estimate and compare the cost-effectiveness of DOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) and vitamin K antagonists (VKAs; warfarin) in preventing stroke among AF patients aged >75 years in real-world practice. Methods: A Markov model with a 10-year span was constructed to estimate the long-term clinical and economic outcomes among AF patients aged >75 years treated with DOACs and warfarin. The study was populated with a hypothetical cohort of 10,000 AF patients aged >75 years. Probabilities of clinical outcomes were obtained from the pooled observational studies (OSs), comparing DOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) with VKAs. Other model inputs, including the utilities and the costs, were all estimated from public sources and the published literature. The costs, quality-adjusted life-years (QAYLs), and incremental cost-effectiveness ratios (ICER) were estimated for each treatment strategy. Subgroup analyses of individual DOACs and the scenario analysis were performed. Uncertainty was evaluated by deterministic sensitivity analysis and probabilistic sensitivity analysis (PSA). Results: Compared to warfarin, DOACs were associated with a gain of 0.36 QALY at an additional cost of $15,234.65, resulting in an ICER of $42,318.47 per QALY. Sensitivity analysis revealed that the ICER was sensitive to the cost of DOACs. Direct oral anticoagulants also shifted from dominating to dominated status When their annual costs of DOACs were over $3,802.84 or the risk ratio of death compared to warfarin was over 1.077%/year. Probabilistic sensitivity analysis (PSA) suggested that DOACs had a 53.83 and 90.7% probability of being cost-effective when the willingness-to-pay threshold was set at $50,000 and $100,000, respectively. Among all the four individual DOACs, edoxaban treatment was revealed as the preferred treatment strategy for the AF patients aged over 75 years by yielding the most significant health gain with the relatively low total cost. Conclusions: Despite the high risk for major bleeding in elderly patients with AF, DOACs are more cost-effective treatment options than warfarin in real-world practice. Edoxaban was the preferred treatment strategy among four kinds of DOACs for AF patients aged over 75 years. Furthermore, beyond their safety profiles, the treatment benefits of DOACs assumed greater relevance and importance in older adults.

The IMPact of untReated nOn-Valvular atrial fibrillation on short-tErm clinical and economic outcomes in the US Medicare population: the IMPROVE-AF model

BACKGROUND

Despite treatment guidelines recommending the use of oral anticoagulants (OACs) for patients with non-valvular atrial fibrillation (NVAF) and moderate to high risk of stroke (CHA₂DS₂-VASc score ≥1), many patients remain untreated. A study conducted among Medicare beneficiaries with AF and a CHA₂DS₂-VASc score of ≥2 found that 51% of patients were not prescribed an OAC despite being eligible for treatment. When left untreated, NVAF poses an enormous burden to society, as stroke events are estimated to cost the US healthcare system about $34 billion each year in both direct medical costs and indirect productivity losses. This research explored the short-term clinical implications and budget impact (BI) of increasing OAC use among Medicare beneficiaries with NVAF.

METHODS

A decision-analytic model was developed from the payer and societal perspectives to estimate the impact of increasing treatment rates among Medicare-eligible NVAF patients with a moderate-to-high risk of stroke over 1 year. Results of the model compared (1) a base case scenario using literature-derived rates of OAC use, and (2) a hypothetical scenario assuming an absolute 5% increase in overall OAC use. Clinical outcomes included the incremental annual number of ischemic stroke, hemorrhagic stroke, and gastrointestinal bleeding events, and stroke-related deaths. Economic outcomes included incremental annual and per-member per-month (PMPM) direct medical costs for the payer perspective and the incremental sum of annual direct medical and indirect costs from productivity loss and caregiver burden for the societal perspective.

RESULTS

In total, 1.95 million Medicare patients with NVAF were estimated to be treated with OACs in the base case (3.8% of beneficiaries). In the hypothetical scenario analysis, nearly 200,000 more patients were treated resulting in 3,705 fewer ischemic strokes, 14 fewer gastrointestinal bleeds, 141 more hemorrhagic strokes, and 175 fewer deaths. The total incremental BI was $399.16 million ($0.65 PMPM) from the payer perspective and $377.10 million from the societal perspective due to indirect cost savings ($22.06 million).

CONCLUSION

Our findings suggest that increased overall OAC use has a positive clinical benefit on the annual number of ischemic stroke events and deaths avoided in the Medicare population, while maintaining a modest increase in the overall BI to the Medicare system.