Cost implications of formulary decisions on oral anticoagulants in nonvalvular atrial fibrillation

Real-world cost-effectiveness of rivaroxaban and apixaban vs VKA in stroke prevention in non-valvular atrial fibrillation in the UK

BACKGROUND

Morbidity and mortality associated with non-valvular atrial fibrillation (NVAF) imposes a substantial economic burden on the UK healthcare system.

OBJECTIVES

An existing Markov model was adapted to assess the real-world cost-effectiveness of rivaroxaban and apixaban, each compared with a vitamin K antagonist (VKA), for stroke prevention in patients with NVAF from the National Health Service (NHS) and personal and social services (PSS) perspective.

METHODS

The model considered a cycle length of 3 months over a lifetime horizon. All inputs were drawn from real-world evidence (RWE): baseline patient characteristics, clinical event and persistence rates, treatment effect (meta-analysis of RWE studies), utility values and resource use. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

The incremental cost per quality-adjusted life year was £14,437 for rivaroxaban, and £20,101 for apixaban, compared with VKA. The probabilities to be cost-effective compared with VKA were 90% and 81%, respectively for rivaroxaban and apixaban, considering a £20,000 threshold. In both comparisons, the results were most sensitive to clinical event rates.

CONCLUSIONS

These results suggest that rivaroxaban and apixaban are cost-effective vs VKA, based on RWE, considering a £20,000 threshold, from the NHS and PSS perspective in the UK for stroke prevention in patients with NVAF. This economic evaluation may provide valuable information for decision-makers, in a context where RWE is more accessible and its value more acknowledged.

Systematic review of societal costs associated with stroke, bleeding and monitoring in atrial fibrillation

Aim: Economic consequences associated with the rise in nonvitamin K antagonist oral anticoagulant use on a societal level remain unclear. Materials & methods: Evidence from the past decade on the societal economic burden associated with stroke, bleeding and international normalized ratio monitoring in atrial fibrillation was collected and summarized through a systematic literature review. Results: There were 14 studies identified that reported indirect costs, which were highest among patients with hemorrhagic stroke and intracranial hemorrhage. The contribution of indirect costs to the total was marginal during acute treatment but substantially increased (30-50%) 2 years after stroke and bleeding events. Conclusion: Limited data were available on societal costs in atrial fibrillation and further research is warranted.

Profiling Clinical Characteristics and Treatment Patterns Among Non-Valvular Atrial Fibrillation Patients: A Real-World Analysis in Dubai, United Arab Emirates

Background:

There is a dearth of real-world evidence regarding patient characteristics, Oral Anti-Coagulant (OAC) treatment, and International Normalized Ratio (INR) patterns in Dubai, United Arab Emirates (UAE).

Methods:

This was a retrospective observational study among newly diagnosed adult Non-valvular Atrial Fibrillation (NVAF) patients in the Dubai Real World Claims Database. Selected patients had at least one activity claim during the 12 months pre-index date (baseline period), and a pharmacy claim for apixaban, dabigatran, rivaroxaban, or warfarin from 01 JAN 2015-31 JUL 2017. Patients with valvular heart disease, cardiac surgery, venous thromboembolism, transient atrial fibrillation, pregnancy, or OAC claims during baseline were excluded. Comorbidities and treatment patterns related to OAC use, index dosing, baseline medications, and INR patterns were described.

Results:

Among 5,072 NVAF patients, 468 met the study criteria. A minority of them (14.3%) were prescribed warfarin, and the most frequently prescribed non-vitamin K antagonist OACs (NOACs) were rivaroxaban (33.3%) and apixaban (31.4%), followed by dabigatran (20.9%). Patients’ mean age was 59 years and mean CHA2DS2-VASc score was 2.3, with most frequent comorbidities of diabetes mellitus, hypertension, coronary artery disease, and peripheral vascular disease. Additionally, 51% and 33% were on statins and aspirin, respectively, while 39% were on other anticoagulant agents. A large proportion of dabigatran patients were on a lower dose (57%). INR patterns revealed 13% of rivaroxaban, 12% of apixaban, and 7% of dabigatran patients had INR claims.

Conclusion:

This study provides relevant insights into the use of OACs in real-world clinical practice settings in Dubai, UAE.

Breadth of complications of long-term oral anticoagulant care

The majority of patients with venous thromboembolism (VTE) have a considerable long-term risk of recurrence and may require extended duration of anticoagulant treatment after the initial 3 to 6 months. The decision to extend treatment is based not only on the individual risk of recurrence, but should also consider the potential complications associated with anticoagulation, taking into account that anticoagulant drugs are among the drugs most frequently associated with hospital admission due to adverse drug reactions. The most feared complication of oral anticoagulants is bleeding, which in some cases may be fatal or may affect critical organs. Case-fatality rates of bleeding have been reported to be ∼3 times higher than case-fatality rates of recurrent VTE. Even when nonserious, bleeding may require medical intervention and/or may impact on patient quality of life or working activity. Factors associated with bleeding during anticoagulant treatment include, among others, advanced age, cancer, renal or liver insufficiency, or concomitant antithrombotic drugs, but no bleeding risk score is sufficiently accurate for use in clinical practice. Not uncommonly, bleeding occurs as a complication of trauma or medically invasive procedures. Nonbleeding complications associated with oral anticoagulants are unusual, and their relevance is extremely uncertain, and include vascular calcification, anticoagulation-related nephropathy, and osteoporosis. Finally, because VTE not uncommonly affects young individuals and the mean age of the population is ∼60 years, the costs associated with extended anticoagulation should not be forgotten. The costs of the drugs need to be balanced against health outcome costs associated with both recurrent VTE and bleeding.

Real-World Health Care Costs Based on Medication Adherence and Risk of Stroke and Bleeding in Patients Treated with Novel Anticoagulant Therapy

BACKGROUND

With the lack of real-world evidence, the challenge for drug reimbursement policy decision makers is to understand medication adherence behavior among users of novel oral anticoagulants (NOACs) and its effect on overall cost savings. No study has examined and quantified the burden of cost in high-risk patients taking NOAC therapy.

OBJECTIVE

To examine the association of cost with adherence, comorbidity, and risk of stroke and bleeding in patients taking NOACs (rivaroxaban and dabigatran).

METHODS

A retrospective cohort study used deidentified data from a commercial managed care database affiliated with Optum Clinformatics Data Mart (January 1, 2010-December 31, 2012). Patients aged 18 years and older with ≥ 1 diagnosis of atrial fibrillation/flutter, > 1 NOAC prescription, 6-month pre-index and 12-month post-index continuous enrollment, and CHA₂DS₂-VASc score ≥ 1 were included. Adherence was calculated using proportion of days covered (PDC ≥ 80%) over an assessment period of 3, 6, and 12 months and compared based on level of comorbidity, stroke, and bleeding risk. The adjusted annual health care costs per patient (drug, medical, and total) were calculated using multivariable gamma regression controlling for demographic and clinical characteristics and compared across groups based on adherence over 12 months, baseline level of comorbidity, and risk of stroke and bleeding.

RESULTS

Of 25,120 NOAC patients, 2,981 patients were included in the final cohort. Based on a PDC threshold of ≥ 80%, the adherence rate over 3, 6, and 12 months was 72%, 65%, and 54%, respectively. For all time periods, the level of adherence significantly increased (P < 0.001), with an increase in stroke risk (based on CHA₂DS₂VASc scores of 1, 2-3, and 4+); comorbidity (Charlson Comorbidity Index scores of 0, 1-2, and 3+); and risk of bleeding (HAS-BLED scores of 0-1, 2, and 3+). Adjusted all-cause total cost calculated for a 12-month period was significantly lower ($29,742 vs. $33,609) among adherent versus nonadherent users. Drug cost was higher ($5,595 vs. $2,233) among adherent versus nonadherent patients but was offset by lower medical costs ($23,544 vs. $30,485) costs. The overall cost significantly increased for patients with a high risk of bleeding and a high level of comorbidity.

CONCLUSIONS

Adherence to NOAC therapy led to a reduction in overall health care cost, since higher drug costs were offset by lower medical (inpatient and outpatient) costs among adherent patients. Cost information based on adherence and risk of stroke and bleeding can help formulary decision makers to assess risk-benefit and help clinicians in developing interventions to reduce patient burden.

DISCLOSURES

Funding to acquire the data source was provided by the University of Rhode Island College of Pharmacy, Kingston, to support PhD dissertation work. Deshpande is currently an employee of Pharmerit International.

Incorporating edoxaban into the choice of anticoagulants for atrial fibrillation

The non-vitamin K antagonist oral anticoagulants (NOACs) are replacing warfarin for stroke prevention in many patients with nonvalvular atrial fibrillation. Edoxaban, an oral factor Xa inhibitor, is the newest entrant in this class. Results of the Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation (ENGAGE AF) study demonstrate that edoxaban is noninferior to warfarin for prevention of stroke and systemic embolic events, and is associated with significantly less major bleeding, including intracranial bleeding, and reduced cardiovascular mortality. With a net clinical benefit over warfarin, edoxaban is well positioned as a choice among the NOACs, which include dabigatran, rivaroxaban, and apixaban. But how will clinicians choose amongst them? The purpose of this paper is to (a) place the ENGAGE AF trial results into context with results of the studies with the other NOACs, and (b) aid clinicians in selection of the right anticoagulant for the right atrial fibrillation patient.

Quality of Pharmacist-Managed Anticoagulation Therapy in Long-Term Ambulatory Settings: A Systematic Review

OBJECTIVE

To perform a systematic review to evaluate the quality of warfarin anticoagulation control in outpatient pharmacist-managed anticoagulation services (PMAS) compared with routine medical care (RMC).

DATA SOURCES

MEDLINE, SCOPUS, EMBASE, IPA, CINAHL, and Cochrane CENTRAL, from inception to May 2017. Search terms employed: ("pharmacist-managed" OR "pharmacist-provided" OR "pharmacist-led" OR "pharmacist-directed") AND ("anticoagulation services" OR "anticoagulation clinic" OR "anticoagulation management" OR "anticoagulant care") AND ("quality of care" OR "outcomes" OR "bleeding" OR "thromboembolism" OR "mortality" OR "hospitalization" OR "length of stay" OR "emergency department visit" OR "cost" OR "patient satisfaction").

STUDY SELECTION AND DATA EXTRACTION

Criteria used to identify selected articles: English language; original studies (comments, letters, reviews, systematic reviews, meta-analyses, editorials were excluded); warfarin use; outpatient setting; comparison group present; time in therapeutic range (TTR) included as a measure of quality of anticoagulant control; study design was not a case report.

DATA SYNTHESIS

Of 177 articles identified, 25 met inclusion criteria. Quality of anticoagulation control was better in the PMAS group compared with RMC in majority of the studies (N = 23 of 25, 92.0%). Clinical outcomes were also favorable in the PMAS group as evidenced by lower or equal risk of major bleeding (N = 10 of 12, 83.3%) or thromboembolic events (N = 9 of 10, 90.0%), and lower rates of hospitalization or emergency department visits (N = 9 of 9, 100%). When reported, PMAS have also resulted in cost-savings in all (N=6 of 6, 100%) of studies.

CONCLUSIONS

Compared with routine care, pharmacist-managed outpatient-based anticoagulation services attained better quality of anticoagulation control, lower bleeding and thromboembolic events, and resulted in lower health care utilization.

Financial Impact of Direct-Acting Oral Anticoagulants in Medicaid: Budgetary Assessment Based on Number Needed to Treat

BACKGROUND

Faced with rising healthcare costs, state Medicaid programs need short-term, easily calculated budgetary estimates for new drugs, accounting for medical cost offsets due to clinical advantages.

OBJECTIVE

To estimate the budgetary impact of direct-acting oral anticoagulants (DOACs) compared with warfarin, an older, lower-cost vitamin K antagonist, on 12-month Medicaid expenditures for nonvalvular atrial fibrillation (NVAF) using number needed to treat (NNT).

METHOD

Medicaid utilization files, 2009 through second quarter 2015, were used to estimate OAC cost accounting for generic/brand statutory minimum (13/23%) and assumed maximum (13/50%) manufacturer rebates. NNTs were calculated from clinical trial reports to estimate avoided medical events for a hypothetical population of 500,000 enrollees (approximate NVAF prevalence × Medicaid enrollment) under two DOAC market share scenarios: 2015 actual and 50% increase. Medical service costs were based on published sources. Costs were inflation-adjusted (2015 US$).

RESULTS

From 2009-2015, OAC reimbursement per claim increased by 173 and 279% under maximum and minimum rebate scenarios, respectively, while DOAC market share increased from 0 to 21%. Compared with a warfarin-only counterfactual, counts of ischemic strokes, intracranial hemorrhages, and systemic embolisms declined by 36, 280, and 111, respectively; counts of gastrointestinal hemorrhages increased by 794. Avoided events and reduced monitoring, respectively, offset 3-5% and 15-24% of increased drug cost. Net of offsets, DOAC-related cost increases were US$258-US$464 per patient per year (PPPY) in 2015 and US$309-US$579 PPPY after market share increase.

CONCLUSIONS

Avoided medical events offset a small portion of DOAC-related drug cost increase. NNT-based calculations provide a transparent source of budgetary-impact information for new medications.

Targeting stroke risk and improving outcomes in patients with atrial fibrillation in Latin America

CONTEXT AND OBJECTIVE:

To examine stroke risk factors, including atrial fibrillation, management and prevention, and stroke outcomes across Latin America.

DESIGN AND SETTING:

Narrative review conducted at Piedmont Heart Institute, United States.

METHODS:

The PubMed, Embase and Cochrane databases were searched for stroke AND "Latin America" AND epidemiology (between January 2009 and March 2015). Further studies in the SciELO, World Health Organization and Pan-American Health Organization databases were used to address specific points.

RESULTS:

Countries categorized as low or middle-income nations by the World Bank, which includes most of Latin America, account for two-thirds of all strokes. Globally, fewer than half of patients (median treatment level: 43.9%) with atrial fibrillation receive adequate anticoagulation to reduce stroke risk, which correlates with data from Latin America, where 46% of outpatients did not receive guideline-compliant anticoagulation, ranging from 41.8% in Brazil to 54.8% in Colombia.

CONCLUSIONS:

Atrial fibrillation-related stroke carries a heavy burden. Non-vitamin K antagonist oral anti-coagulants provide options for reducing the risk of atrial fibrillation-related stroke. However, cost-effectiveness comparisons with warfarin are warranted before observational health-economics study results can be applied clinically. Initiatives to remedy inequalities and improve access to care across Latin America should accompany risk factor modification and guideline-based prevention.

Antithrombotic Usage Patterns in the Era of New Oral Anticoagulant Options for Atrial Fibrillation

BACKGROUND

Appropriate treatment reduces the risk of stroke in patients with atrial fibrillation (AF). Despite the known benefits of warfarin, anticoagulation prescribing rates remain inadequate in high-risk patients. Over the last 6 years, 4 novel oral anticoagulants have been approved for use for stroke prophylaxis in non-valvular AF (NVAF), which may allow prescribers to tailor therapy for each NVAF patient.

OBJECTIVE

The goal of this investigation was to determine the effect of dabigatran and rivaroxaban availability on the rate of anticoagulant prescribing at hospital discharge in patients with a principal diagnosis of NVAF.

METHODS

A retrospective chart review of adult patients presenting with NVAF (CHADS2 score ≥2) was conducted using a historical control group of patients from 2009 compared to patients admitted in 2012 following formulary availability of dabigatran and rivaroxaban. In addition to antithrombotic therapy prescribed, subsequent hospitalizations during a 1-year period were reviewed for major bleeding and stroke events.

RESULTS

Two hundred patients were enrolled in the study. The rate of anticoagulant prescribing in the 2009 and 2012 groups was 68.3% and 77.1%, respectively (p = .16). Of the patients in the 2012 group prescribed an anticoagulant, 58 (64%) received warfarin, 26 (28%) received dabigatran, and 7 (8%) received rivaroxaban. One patient (1.2%) in the 2009 group and 4 patients (4.4%) in the 2012 group had a major bleed (p = .4).

CONCLUSION

There was no statistical difference in the rate of anticoagulant prescribing between the 2 groups. Despite the availability of additional anticoagulant options, the rate of prescribing remains suboptimal in this high-risk population.

Direct-Acting Oral Anticoagulants: Practical Considerations for Emergency Medicine Physicians

Nonvalvular atrial fibrillation- (NVAF-) related stroke and venous thromboembolism (VTE) are cardiovascular diseases associated with significant morbidity and economic burden. The historical standard treatment of VTE has been the administration of parenteral heparinoid until oral warfarin therapy attains a therapeutic international normalized ratio. Warfarin has been the most common medication for stroke prevention in NVAF. Warfarin use is complicated by a narrow therapeutic window, unpredictable dose response, numerous food and drug interactions, and requirements for frequent monitoring. To overcome these disadvantages, direct-acting oral anticoagulants (DOACs)—dabigatran, rivaroxaban, apixaban, and edoxaban—have been developed for the prevention of stroke or systemic embolic events (SEE) in patients with NVAF and for the treatment of VTE. Advantages of DOACs include predictable pharmacokinetics, few drug-drug interactions, and low monitoring requirements. In clinical studies, DOACs are noninferior to warfarin for the prevention of NVAF-related stroke and the treatment and prevention of VTE as well as postoperative knee and hip surgery VTE prophylaxis, with decreased bleeding risks. This review addresses the practical considerations for the emergency physician in DOAC use, including dosing recommendations, laboratory monitoring, anticoagulation reversal, and cost-effectiveness. The challenges of DOACs, such as the lack of specific laboratory measurements and antidotes, are also discussed.

Nonvitamin K antagonist oral anticoagulants in everyday practice: Stroke prevention in atrial fibrillation and treatment of venous thromboembolism

PURPOSE

In recent years, four nonvitamin K antagonist oral anticoagulants (NOACs) were approved to prevent stroke in patients with nonvalvular atrial fibrillation (AF) and to treat venous thromboembolism (VTE). Edoxaban, a direct factor Xa inhibitor, is the latest NOAC to be approved for use by the U.S. Food and Drug Administration. The other NOACs include two direct factor Xa inhibitors, apixaban and rivaroxaban, and one direct thrombin inhibitor, dabigatran. The purpose of this article is to introduce these agents to providers, discuss dosing, and offer insights into practical considerations for each NOAC.

DATA SOURCES

PubMed was searched to identify randomized controlled trials and cost-effectiveness analyses evaluating NOACs. In addition, package inserts for the four NOACs provided pharmacologic data.

CONCLUSIONS

All four NOACs are equivalent to or better than warfarin for the treatment of VTE and stroke prevention in AF, and may reduce the risk of bleeding complications, particularly intracranial bleeding.

IMPLICATIONS FOR PRACTICE

NOACs may benefit some patients by avoiding the numerous food or drug interactions and frequent laboratory monitoring associated with warfarin. Adherence to proper dosing is critical for NOAC efficacy and safety.

Non-vitamin K antagonist oral anticoagulants and atrial fibrillation guidelines in practice: barriers to and strategies for optimal implementation

Stroke is a leading cause of morbidity and mortality worldwide. Atrial fibrillation (AF) is an independent risk factor for stroke, increasing the risk five-fold. Strokes in patients with AF are more likely than other embolic strokes to be fatal or cause severe disability and are associated with higher healthcare costs, but they are also preventable. Current guidelines recommend that all patients with AF who are at risk of stroke should receive anticoagulation. However, despite this guidance, registry data indicate that anticoagulation is still widely underused. With a focus on the 2012 update of the European Society of Cardiology (ESC) guidelines for the management of AF, the Action for Stroke Prevention alliance writing group have identified key reasons for the suboptimal implementation of the guidelines at a global, regional, and local level, with an emphasis on access restrictions to guideline-recommended therapies. Following identification of these barriers, the group has developed an expert consensus on strategies to augment the implementation of current guidelines, including practical, educational, and access-related measures. The potential impact of healthcare quality measures for stroke prevention on guideline implementation is also explored. By providing practical guidance on how to improve implementation of the ESC guidelines, or region-specific modifications of these guidelines, the aim is to reduce the potentially devastating impact that stroke can have on patients, their families and their carers.

Cost-effective prophylaxis against venous thromboembolism after total joint arthroplasty: warfarin versus aspirin

Although recent guidelines suggest aspirin for venous thromboembolism (VTE) prophylaxis in low risk patients following total hip arthroplasty (THA) and total knee arthroplasty (TKA), there are no cost-effectiveness studies comparing aspirin and warfarin. In a Markov cohort cost-effectiveness analysis, we found that aspirin cost less and saved more quality-adjusted life-years (QALYs) than warfarin in all age groups. Cost per QALY gained by aspirin was $24,506.20 at age of 55 and $47,148.10 at the age of 85 following THA and $15,117.20 and $24,458.10 after TKA, which were greater than warfarin. In patients undergoing THA/TKA without prior VTE, aspirin is more cost-effective prophylactic agent than warfarin. Warfarin might be a better prophylaxis in TKA patients with high probability of VTE and very low probability of bleeding.