Evaluation of medical costs associated with use of new oral anticoagulants compared with standard therapy among venous thromboembolism patients

Economic Evaluation of Direct Oral Anticoagulants Compared to Warfarin for Venous Thromboembolism in Thailand: A Cost-Utility Analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been used for venous thromboembolism (VTE) in Thailand. However, they have not been listed in the National List of Essential Medicines (NLEM). A cost-effectiveness analysis is needed to aid policymakers in deciding whether DOACs should be listed in the NLEM. This study aimed to assess the cost-effectiveness of DOACs for patients with VTE in Thailand.

METHODS

A cohort-based state transition model was constructed from a societal perspective with a lifetime horizon. All available DOACs, including apixaban, rivaroxaban, edoxaban, and dabigatran, were compared with warfarin. A 6-month cycle length was used to capture all costs and health outcomes. The model consisted of nine health states, including VTE on treatment, VTE off treatment, recurrent VTE, clinically relevant non-major bleeding, gastrointestinal bleeding, intracranial bleeding, post-intracranial bleeding, chronic thromboembolic pulmonary hypertension, and death. All inputs were based on a comprehensive literature review. The model outcomes included total cost and quality-adjusted life-years (QALYs) with a 3% annual discount rate. A fully incremental cost-effectiveness analysis and the incremental cost-effectiveness ratio (ICER) per QALY gained were calculated at a willingness-to-pay (WTP) of THB 160,000/QALY ($5003). The robustness of the findings was assessed using deterministic and probabilistic sensitivity analyses.

RESULTS

All DOACs were associated with a decreased risk of VTE recurrence and intracranial hemorrhage. In the base-case analysis, apixaban could increase 0.16 QALYs compared with warfarin. An ICER for apixaban was 269,809 Thai baht (THB)/QALY ($8437/QALY). Rivaroxaban had a better QALY than warfarin at 0.09 QALYs with an ICER of 757,363 THB/QALY ($23,682/QALY). Edoxaban and dabigatran could also increase by 0.10 QALYs with an ICER of 709,945 THB ($22,200) and 707,145 THB ($22,122)/QALY, respectively. Our probabilistic sensitivity analyses indicated that warfarin had a 99.8% possibility of being cost-effective, while apixaban had a 0.2% possibility of being cost-effective at the current WTP. Other DOACs had no possibility of being cost-effective.

CONCLUSIONS

All DOACs were not cost-effective for VTE treatment at the current WTP in Thailand. Apixaban is likely to be the best option among DOACs.

Clinician Trends in Prescribing Direct Oral Anticoagulants for US Medicare Beneficiaries

IMPORTANCE

Contemporary national clinical practice guidelines recommend direct-acting oral anticoagulants (DOACs) as the first-line anticoagulant strategy over warfarin for most indications, especially among older individuals with an elevated bleeding risk.

OBJECTIVE

To evaluate anticoagulant prescribing and DOAC uptake by US clinicians in the Medicare population.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included all US clinicians with more than 10 Medicare oral anticoagulant prescription claims, who were included in the national Medicare Provider Utilization and Payment Data (2013-2018). Data analyses were conducted between October 2020 and October 2021.

EXPOSURES

DOAC prescription in 2013.

MAIN OUTCOMES AND MEASURES

Clinicians were categorized based on 2013 prescribing as solely prescribing warfarin, DOAC, or both, and their temporal trajectories of proportionate DOAC use were examined.

RESULTS

The analysis included 325 666 unique clinicians with more than 10 oral anticoagulant prescriptions between 2013 and 2018 (26 620 [8.2%] cardiologists, 85 563 [26.3%] internal medicine physicians, 84 369 [25.9%] family medicine physicians, and 81 161 [24.9%] advanced practice clinicians, including nurse practitioners and physician assistants). In 2013, among 91 837 prescribers, 54 501 (59.3%) prescribed only warfarin, 1918 (2.1%) prescribed only a DOAC, and 35 418 (38.6%) prescribed both. During the study period, the number of clinicians prescribing DOACs increased, but 19% continued to prescribe only warfarin in 2018. While 359 cardiologists prescribing anticoagulants (1.6%) were warfarin-only prescribers, 10 414 (20.0%) and 6296 (12.6%) of family and internal medicine physicians also prescribed only warfarin, respectively. Clinicians prescribing only warfarin in 2013 had lower proportionate DOAC use throughout the study compared with 2013 DOAC prescribers, which represents a median (IQR) of 41.9% (20.3%-61.9%) of their anticoagulant prescriptions in 2018 vs 67.0% (49.9%-82.8%) for DOAC prescribers.

CONCLUSIONS AND RELEVANCE

Despite the increase in DOAC use among Medicare beneficiaries, many clinicians in this study continued to use warfarin as their predominant or only anticoagulant instead of DOACs. There is a need to address barriers to the uptake of these medications to realize their potential benefits for patients.

American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), occurs in ∼1 to 2 individuals per 1000 each year, corresponding to ∼300 000 to 600 000 events in the United States annually.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about treatment of VTE.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and adult patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 28 recommendations for the initial management of VTE, primary treatment, secondary prevention, and treatment of recurrent VTE events.

CONCLUSIONS

Strong recommendations include the use of thrombolytic therapy for patients with PE and hemodynamic compromise, use of an international normalized ratio (INR) range of 2.0 to 3.0 over a lower INR range for patients with VTE who use a vitamin K antagonist (VKA) for secondary prevention, and use of indefinite anticoagulation for patients with recurrent unprovoked VTE. Conditional recommendations include the preference for home treatment over hospital-based treatment for uncomplicated DVT and PE at low risk for complications and a preference for direct oral anticoagulants over VKA for primary treatment of VTE.

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 literature review of treatment patterns for venous thromboembolism patients during transitions from inpatient to post-discharge settings

Introduction

Direct oral anticoagulants (DOACs) have emerged as viable alternatives to traditional treatments such as vitamin K antagonists (VKAs) for venous thromboembolism (VTE). The objective of this review was to summarize evidence on the use of DOACs and VKAs to treat VTE in the US for patients transitioning from inpatient to post-discharge settings.

Materials and methods

A systematic review of the VTE literature identified studies published in English (January 1, 2011–December 31, 2016) that reported inpatient and post-discharge treatments and discharge location. Two reviewers screened abstracts, abstracted information from included studies, and assessed the quality of the study methodology and reporting.

Results

Forty-nine studies were included (24 clinical and 25 economic). A limited number of studies (eight clinical and three economic) examined VTE treatment patterns during transitions of care from inpatient to post-discharge settings, irrespective of anticoagulant (eg, DOAC, warfarin, heparin), and < 25% of all studies reported a post-discharge location. Three clinical studies that reported inpatient and outpatient treatment found better patient outcomes with DOAC vs warfarin. Fourteen economic studies reported that DOACs were associated with shorter hospital length of stay (LOS) and lower direct costs vs warfarin. No studies reported indirect costs.

Discussion

Although DOACs are associated with shorter LOS, lower costs, and better patient outcomes vs VKAs, it appears in one study that only a small percentage of patients with stable VTE who are discharged to home may be receiving DOACs.

Conclusion

These findings identified the potential areas of opportunity to improve the management of VTE through coordination of care from the inpatient to the outpatient settings.

The Use of Edoxaban in Patients with Nonvalvular Atrial Fibrillation and Venous Thromboembolism: A Pharmacist's Perspective

Until 2010, the vitamin K antagonist warfarin was the only available oral anticoagulant for the prevention of stroke or systemic embolic events (SEE) in patients with nonvalvular atrial fibrillation (NVAF) and the treatment of venous thromboembolism (VTE) in the United States. Despite its proven efficacy, the use of warfarin is limited by numerous disadvantages, including a delayed onset of action and variable efficacy resulting from interactions with genetic and environmental factors. Consequently, optimal anticoagulation with warfarin requires dose adjustments based on frequent monitoring. In contrast to warfarin, direct oral anticoagulants (DOACs) including dabigatran, rivaroxaban, apixaban, and edoxaban have predictable pharmacokinetic profiles, few drug-drug interactions, no known interactions with food, and can be administered at fixed doses without the requirement for routine monitoring. All DOACs have received US Food and Drug Administration (FDA) approval for the prevention of stroke or SEE in patients with NVAF and the treatment of VTE based on phase 3 trials demonstrating that they are at least as efficacious as warfarin. In addition, the incidence of clinically relevant bleeding associated with DOACs is comparable to or lower than with warfarin. In this article, the preclinical and clinical data that led to the FDA approval of once-daily edoxaban in January 2015 are presented. Furthermore, practical considerations for edoxaban use including dosing recommendations, transitions of care, reversal of anticoagulation, precautions, contraindications, and cost-effectiveness are discussed. Edoxaban is an important addition to oral anticoagulation options available for the therapeutic management of patients with NVAF or VTE.

Reducing the risk of venous thromboembolism using apixaban - patient perspectives and considerations. Should more attention be given to females?

BACKGROUND

New oral anticoagulant agents, such as apixaban, rivaroxaban, dabigatran, or endoxaban, have recently become for patients an alternative option to conventional treatment in the therapy of venous thromboembolism (VTE). Thus, we aimed to review the available information on adverse events (AEs) of apixaban compared to conventional therapy (heparin or vitamin K antagonists) in randomized controlled trials (RCTs) on patients treated for VTE, with a particular attention to sex subgroups.

METHODS

An electronic search in MEDLINE and Embase was performed by using the keywords "apixaban" and "venous thromboembolism". All RCTs focused on apixaban in the treatment and prevention of VTE were evaluated for the presence of AEs. AEs were classified as serious, bleeding, and cause of discontinuation. Moreover, we also searched by using the keywords "gender" and "venous thromboembolism" and "anticoagulants".

RESULTS

Considering all subjects enrolled in the eleven RCTs as a whole to investigate the occurrence of AEs, we extrapolated an events/subjects rate of 57.8% for AEs (6,445/11,144), 7.7% for serious AEs (975/12,647), 9.1% for bleeding events (1,229/13,454), and 3.2% for discontinuation of apixaban (421/13,039). The percentage of AEs was lower in subjects treated with apixaban than in those treated with conventional VTE therapy (53% vs 56.3%, respectively). However, only one study provided data on separate analysis by sex of either efficacy or safety of apixaban.

CONCLUSION

Under the patient's perspective, apixaban could represent a good choice in the treatment of VTE, due to its pharmacological, economical, and safety profile. These positive aspects are certainly present in both sexes, since the available studies include a correct percentage of women, but data with separate analyses by sex are extremely limited. Future clinical trials should include in their results on clinical impact and outcomes a stratification by sex, and studies aimed to evaluate possible sex-related differences for these drugs should be strongly encouraged.

Choosing Non-Vitamin K Antagonist Oral Anticoagulants: Practical Considerations We Need to Know

BACKGROUND

Warfarin is a well-established agent for use in the prevention of stroke or systemic embolic event (SEE) in patients with nonvalvular atrial fibrillation (NVAF) and for the treatment of venous thromboembolism (VTE). However, management of patients requiring oral anticoagulation with warfarin can be complicated by the need for frequent monitoring, drug-drug and drug-food interactions, and a variable response based on genetic polymorphisms. The non-vitamin K antagonist oral anticoagulants (NOACs) were developed as alternatives to warfarin; they do not require routine monitoring and have predictable pharmacokinetics, fewer drug-drug interactions, and limited drug-food interactions. Four NOACs-dabigatran, rivaroxaban, apixaban, and edoxaban-have received approval from the US Food and Drug Administration for the prevention of stroke or SEE in NVAF and for the treatment of VTE. Selecting the most appropriate agent for each patient should be done in consideration of patient preferences and characteristics, including renal function, bleeding risk, and the need for other medications.

METHODS

A search was performed on the terms atrial fibrillation and venous thromboembolism with individual terms dabigatran, apixaban, edoxaban, or rivaroxaban to identify relevant manuscripts; large randomized clinical trials, metaanalyses, and treatment guideline recommendations were given preference. Searches to identify registries, treatment guidelines, and metaanalyses relevant to specific subgroups were also used.

RESULTS

NOACs are effective in reducing the risk of stroke or SEE in patients with NVAF and are associated with fewer incidents of intracranial bleeding vs warfarin.

CONCLUSION

NOACs provide a convenient and safe alternative to warfarin and may result in improved therapeutic outcomes for patients with NVAF or VTE. The use of NOACs in other indications and patient populations is under investigation, and clinical trials investigating their use in acute coronary syndrome, medically ill patients, percutaneous coronary intervention, cardioversion, catheter ablation, coronary arterial disease, and heart failure have been announced.

Incremental Health Care Burden of Bleeding Among Patients with Venous Thromboembolism in the United States

BACKGROUND

The health care and economic burden of venous thromboembolism (VTE) has been evaluated in regard to acute VTE, VTE recurrence, and some VTE complications, such as postthrombotic syndrome, but the cost burden attributed to bleedings is not well understood.

OBJECTIVE

To evaluate health care resource utilization and costs associated with major bleeding (MB) and clinically relevant nonmajor bleeding (CRNMB) among a large U.S. commercially and Medicare-insured population with VTE.

METHODS

Patients (≥ 18 years of age, continuously insured) with a diagnosis of VTE between January 1, 2008, and December 31, 2011, were identified from the Truven Health Analytics Commercial and Medicare MarketScan databases. Patients who did not have any bleedings during the study period were grouped into a no-bleedings cohort and a random date after VTE diagnosis was selected as the index date. VTE patients who experienced MB within 1 year of the initial VTE diagnosis were grouped into a MB cohort, and patients without MB but with CRNMB were grouped into a CRNMB cohort. Baseline patient demographics and clinical characteristics were determined for study cohorts. All-cause and bleeding-related health care resource utilization and costs (inflation adjusted to 2013 level) during a 12-month follow-up period after the index date of the initial bleeding event were measured and compared. Descriptive statistics were used to evaluate differences in demographics, clinical characteristics, and unadjusted health care resource utilization and costs of patient cohorts. Multivariable generalized linear models were used to evaluate incremental health care costs of bleedings after adjusting for key patient characteristics.  

RESULTS

Among the 112,885 patients identified with a VTE diagnosis, 14% (n = 15,897) had MB and 14% (n = 15,842) had CRNMB; 72% (n = 81,146) had neither of these events occur during the study period. The mean ages of the MB and CRNMB cohorts were both 63.6 years, while the mean age of the no-bleedings cohort was significantly lower at 59.6 years (P  less than  0.001). Mean Charlson Comorbidity Index scores were highest for the MB cohort (3.2), followed by those of the CRNMB cohort (2.5) and the no-bleedings cohort (1.6). The MB cohort had the greatest proportion of patients with an initial VTE event of pulmonary embolism only (23.5%), followed by that of the CRNMB cohort (20.2%), and the no-bleedings cohort (16.7%). For MB and CRNMB cohorts, the total mean bleeding-related inpatient and outpatient costs during the follow-up period were $49,779 (SE = $820) and $2,187 ($89), respectively. After adjustment for key patient characteristics, the estimated mean differences in total bleeding-related medical costs were $45,367 ($1,853) for patients with MB and $2,140 ($88) for patients with CRNMB versus patients with no bleedings.

CONCLUSIONS

Among patients with VTE diagnosis in the United States, approximately 28% have a bleeding event within 1 year of VTE diagnosis, and about half of these patients experience MB. Patients with MB have greatly elevated health care costs.

Comparison of differences in medical costs when new oral anticoagulants are used for the treatment of patients with non-valvular atrial fibrillation and venous thromboembolism vs warfarin or placebo in the US

OBJECTIVE

Medical costs that may be avoided when any of the four new oral anticoagulants (NOACs), dabigatran, rivaroxaban, apixaban, and edoxaban, are used instead of warfarin for the treatment of non-valvular atrial fibrillation (NVAF) were estimated and compared. Additionally, the overall differences in medical costs were estimated for NVAF and venous thromboembolism (VTE) patient populations combined.

METHODS

Medical cost differences associated with NOAC use vs warfarin or placebo among NVAF and VTE patients were estimated based on clinical event rates obtained from the published trial data. The clinical event rates were calculated as the percentage of patients with each of the clinical events during the trial periods. Univariate and multivariate sensitivity analyses were conducted for the medical-cost differences determined for NVAF patients. A hypothetical health plan population of 1 million members was used to estimate and compare the combined medical-cost differences of the NVAF and VTE populations and were projected in the years 2015-2018.

RESULTS

In a year, the medical-cost differences associated with NOAC use instead of warfarin were estimated at -$204, -$140, -$495, and -$340 per patient for dabigatran, rivaroxaban, apixaban, and edoxaban, respectively. In 2014, among the hypothetical population, the medical-cost differences were -$3.7, -$4.2, -$11.5, and -$6.6 million for NVAF and acute VTE patients treated with dabigatran, rivaroxaban, apixaban, and edoxaban, respectively. In 2014, for the combined NVAF, acute VTE, and extended VTE patient populations, medical-cost differences were -$10.0, -$10.9, -$21.0, and -$21.0 million for dabigatran, rivaroxaban, 2.5 mg apixaban, and 5 mg apixaban, respectively. Medical-cost differences associated with use of NOACs were projected to steadily increase from 2014 to 2018.

CONCLUSIONS

Medical costs are reduced when NOACs are used instead of warfarin/placebo for the treatment of NVAF or VTE, with apixaban being associated with the greatest reduction in medical costs.

Real-World Medical Cost Avoidance When New Oral Anticoagulants are Used Versus Warfarin for Venous Thromboembolism in the United States

OBJECTIVE

Real-world medical cost avoidances from a US payer perspective were estimated when new oral anticoagulants (NOACs) are used instead of warfarin for the treatment of patients with venous thromboembolism (VTE).

METHODS

Reductions in real-world event rates of recurrent VTE and MB were obtained by applying rate reductions from the NOACs versus warfarin trials to the Worcester population. Incremental annual medical costs among patients with VTE and MB from a US payer perspective were obtained from the literature or claims databases. Differences in total medical costs for patients treated with NOACs versus warfarin were then estimated. Univariate and Monte Carlo sensitivity analyses were additionally carried out.

RESULTS

The annual total medical cost avoidances versus warfarin were greatest for VTE patients treated with apixaban (-US$4440 per patient-year [ppy]), followed by those treated with rivaroxaban (-US$2971 ppy), edoxaban (-US$1957 ppy), and dabigatran (-US$572 ppy). The medical cost avoidances remained consistent under sensitivity analyses.

CONCLUSION

Based on real-world data, when any of the evaluated NOACs are used instead of warfarin for treatment of patients with acute VTE, annual medical costs are reduced. Of the NOACs, apixaban has the greatest real-world medical cost avoidance, as its use is associated with substantial reductions in both VTE and MB event rates.