Cost effectiveness of warfarin versus aspirin in patients older than 75 years with atrial fibrillation

To treat or not to treat: a comparative effectiveness analysis of oral anticoagulant outcomes among U.S. nursing home residents with atrial fibrillation

BACKGROUND

Nursing home residents with atrial fibrillation are at high risk for ischemic stroke, but most are not treated with anticoagulants. This study compared the effectiveness and safety between oral anticoagulant (OAC) users and non-users.

METHODS

We conducted a new-user retrospective cohort study by using Minimum Data Set 3.0 assessments linked with Medicare claims. The participants were Medicare fee-for-service beneficiaries with atrial fibrillation residing in US nursing homes between 2011 and 2016, aged ≥ 65 years. The primary outcomes were occurrence of an ischemic stroke or systemic embolism (effectiveness), occurrence of intracranial or extracranial bleeding (safety) and net clinical outcome (effectiveness or safety outcomes). Secondary outcomes included total mortality and a net clinical and mortality outcome. Cox proportional hazards and Fine and Grey models estimated multivariable adjusted hazard ratios (aHRs) and sub-distribution hazard ratios (sHRs).

RESULTS

Outcome rates were low (effectiveness: OAC: 0.86; non-users: 1.73; safety: OAC: 2.26; non-users: 1.75 (per 100 person-years)). OAC use was associated with a lower rate of the effectiveness outcome (sHR: 0.69; 95% Confidence Interval (CI): 0.61-0.77), higher rates of the safety (sHR: 1.70; 95% CI: 1.58-1.84) and net clinical outcomes (sHR: 1.20; 95% CI: 1.13-1.28) lower rate of all-cause mortality outcome (sHR: 0.60; 95% CI: 0.59-0.61), and lower rate of the net clinical and mortality outcome (sHR: 0.60; 95% CI: 0.59-0.61). Warfarin users, but not DOAC users, had a higher rate of the net clinical outcome versus OAC non-users.

CONCLUSIONS

Our results support the benefits of treatment with OACs to prevent ischemic strokes and increase longevity, while highlighting the need to weigh apparent benefits against elevated risk for bleeding. Results were consistent with net favorability of DOACs versus warfarin.

Discontinuation of oral anticoagulant use among nursing home residents with atrial fibrillation before hospice enrollment

BACKGROUND

Oral anticoagulants (OACs) are effective in reducing the risk of cardioembolic stroke due to atrial fibrillation. While most nursing home residents with atrial fibrillation qualify for anticoagulation based on clinical guidelines, the net clinical benefits of OACs may diminish as residents approach the end of life.

METHODS

We conducted a cross-sectional study of 30,503 US nursing home residents with atrial fibrillation (based on Minimum Data Set 3.0 and Medicare Part A records) who used OACs in the year before enrolling in hospice care during 2012-2016. Whether residents discontinued OACs before hospice enrollment was determined using Part D claims and date of hospice enrollment. Modified Poisson models estimated adjusted prevalence ratios (aPR).

RESULTS

Almost half (45.7%) of residents who had recent OAC use discontinued prior to hospice enrollment. Residents who were underweight (aPR: 1.02; 95% confidence interval [CI]: 1.01-1.03), those with high bleeding risk (aPR: 1.04, 95% CI: 1.03-1.05), and those with moderate or severe cognitive impairment (aPR: 1.02, 95% CI: 1.02-1.03) had a higher prevalence of OAC discontinuation before entering hospice. Residents with venous thromboembolism (aPR: 0.94, 95% CI: 0.93-0.96), statin users (aPR: 0.88, 95% CI: 0.87-0.89), and those on polypharmacy (≥10 medications, aPR: 0.72; 95% CI: 0.71-0.73) were less likely to discontinue OACs before enrollment in hospice.

CONCLUSION

Anticoagulants are often discontinued among older nursing home residents with atrial fibrillation before hospice enrollment; it is not clear that these decisions are driven solely by net clinical benefit considerations. Further research is needed on comparative outcomes to inform resident-centered decisions regarding OAC use in older adults entering hospice.

Role of PFO Closure in Ischemic Stroke Prevention

PURPOSE OF REVIEW

To highlight recent advancements in the management of acute ischemic stroke patients with patent foramen ovale (PFO).

RECENT FINDINGS

One significant recent development was publication of long-term follow-up data from the RESPECT trial demonstrating evidence in favor of PFO closure over medical management. This data subsequently led to FDA approval for AMPLATZER™ septal occluder in the treatment of patients aged 18 to 60 years with both PFO and no other determined etiology for ischemic stroke, otherwise referred to as embolic stroke of undetermined source. Several subsequent closure trial results have recently been published, which also demonstrated benefit of PFO closure over medical management for ischemic stroke risk reduction in select patients. Based on the results of the more recently published REDUCE trial, the FDA granted approval for the GORE™ septal occluder. There is current, well-established evidence that PFO closure for secondary stroke prevention is effective in select cases.

Economic Evaluation of the Combined Use of Warfarin and Low-dose Aspirin Versus Warfarin Alone in Mechanical Valve Prostheses

BACKGROUND

The use of combined therapy of antiplatelet and anticoagulant versus anticoagulant alone to reduce instances of thromboembolic events in patients with heart valve prostheses is an established standard of care in many countries but not in Egypt. A previous Markov model cost-effectiveness study on Egyptian patients aged 50-60 years demonstrated that the combined therapy reduces the overall treatment cost. However, due to the lack of actual real-world data on cost-effectiveness and the limitation of the Markov model study to 50- to 60-year-old patients, the Egyptian medical community is still questioning whether the added benefit is worth the cost.

OBJECTIVE

To assess, from the perspective of the Egyptian health sector, the cost-effectiveness of the combined use of warfarin and low-dose aspirin (75 mg) versus that of warfarin alone in patients with mechanical heart valve prostheses who began therapy between the age of 15 and 50 years.

METHODS

An economic evaluation was conducted alongside a randomized, controlled trial to assess the cost-effectiveness of the combined therapy in patients with mechanical valve prostheses. A total of 316 patients aged between 15 and 50 years were included in the study and randomly assigned to a group treated with both warfarin and aspirin or a group treated with warfarin alone.

RESULTS

The patients in the combined therapy group exhibited a significantly longer duration of protection against the first event. Fewer primary events were observed in the patients treated with warfarin plus aspirin than in those treated with warfarin alone (1.4 %/year, vs. 4.8 %/year), and a higher mean quality-adjusted life-years (QALYs) value over 4 years was obtained for the group treated with warfarin plus aspirin (difference 0.058; 95 % CI 0.013-0.118), although this difference did not reach a conventional level of statistical significance. The total costs over a 4-year period were lower with the combined therapy (difference -US$244; 95 % CI -US$483.1 to -US$3.8), which yielded an incremental cost-effectiveness ratio of -US$4206 per QALY gained. Thus, the combined therapy was dominant. All costs were reported in US dollars (USD) for the financial year 2014.

CONCLUSIONS

The results of this analysis indicate that from the perspective of the Egyptian health sector, the addition of aspirin to the typical warfarin therapy is more effective and less costly for patients with mechanical valve prostheses than treatment with warfarin alone. This combined strategy could be adopted to prevent the complications of mechanical valve prostheses. Our study adds to the body of evidence supporting the option of warfarin-plus-aspirin therapy for patients with mechanical valve prostheses.

Cost-effectiveness of edoxaban versus rivaroxaban for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in the US

BACKGROUND

Understanding the value of new anticoagulation therapies compared with existing therapies is of paramount importance in today's cost-conscious and efficiency-driven health care environment. Edoxaban and rivaroxaban for stroke prevention in nonvalvular atrial fibrillation (NVAF) patients with CHADS2 scores ≥2 have been evaluated in pivotal trials versus warfarin. The relative value of edoxaban versus rivaroxaban would be of interest to health care stakeholders and patients who prefer a once-daily treatment option for long-term stroke prevention in NVAF.

OBJECTIVE

To evaluate the relative cost-effectiveness of two once-daily regimens of novel oral anticoagulation therapy - edoxaban (60 mg/30 mg dose-reduced) versus rivaroxaban (20 mg/15 mg dose-reduced) - for stroke prevention in NVAF patients from a US health-plan perspective.

MATERIALS AND METHODS

A Markov model simulated lifetime risk and treatment of stroke, systemic embolism, major bleeding, clinically relevant nonmajor bleeding, myocardial infarction, and death in NVAF patients treated with edoxaban or rivaroxaban. Efficacy and safety data were derived from a network meta-analysis that utilized data from patients enrolled in ENGAGE AF-TIMI 48 and ROCKET-AF. Health care cost and utility data were obtained from published sources. Incremental cost-effectiveness ratios of $150,000 per quality-adjusted life year (QALY) gained were used as thresholds for "highly cost-effective", "cost-effective", and "not cost-effective" treatment options, respectively, as per American Heart Association/American College of Cardiology guidelines.

RESULTS

Edoxaban was dominant relative to rivaroxaban, such that it was associated with lower total health care costs and better effectiveness in terms of QALYs in the base-case analysis. Results were supported by probabilistic sensitivity analyses that showed edoxaban as either dominant or a highly cost-effective alternative (incremental cost-effectiveness ratio <$50,000) to rivaroxaban in 88.4% of 10,000 simulations.

CONCLUSION

Results of this study showed that the once-daily edoxaban (60 mg/30 mg dose-reduced) regimen is a cost-saving or highly cost-effective treatment relative to rivaroxaban (20 mg/15 mg dose-reduced) for stroke prevention in NVAF patients with CHADS2 ≥2.

Implementing Guidelines: The Cost and Clinical Impact of Anticoagulants in the UK Atrial Fibrillation Population

BACKGROUND

Updated treatment guidelines for atrial fibrillation (AF) have been released by the National Institute for Health and Care Excellence (NICE) in the UK, and highlight a current shortfall in the prescription of anticoagulants to patients with AF for stroke prevention.

OBJECTIVE

To design a budget impact model as a planning tool for UK Clinical Commissioning Groups (CCGs) looking to budget for greater use of anticoagulants in the AF population.

METHODS

An Excel® model was developed to estimate the five-year impact of gradually treating all eligible patients with AF who are currently not being prescribed anticoagulants, both in terms of the effect on key clinical outcomes (strokes, major bleeds and mortality) and the associated financial impact.

RESULTS

For a population of 251,693 (average CCG size) with an estimated 2626 prevalent patients and an additional 546 incident cases annually, the model estimated that increasing the proportion of the eligible AF patient population receiving anticoagulation by a fraction would require an additional budget of GBP139,961 in Year 1 to treat an additional 314 patients. This would rise to GBP1,004,900 in Year 5 to treat an additional 2242 patients, with all eligible patients treated by this year. The price year was 2014. Over the 5-year timeframe, this could lead to the prevention of 24 strokes and 29 deaths, with an increase of 31 major bleeds.

CONCLUSIONS

The clinical benefits of appropriate anticoagulation are widely recognised; however, full implementation can be difficult and costly. Therefore, the development of models can support the planning process by facilitating discussion among stakeholders on how best they can reach full implementation. The model is flexible and can be adapted to suit different payers.

Evidence-to-practice gaps in post-stroke management: a focus on care in a stroke unit and anticoagulation to prevent death, disability and recurrent stroke

ABSTRACT: 

The global burden of stroke is large. Over the last 15 years significant advances have been made to improve acute stroke care and prevention management providing the ability to mitigate much of this burden. In this article, we describe the importance of two main elements of stroke care: stroke units to reduce death and disability and anticoagulation therapy to prevent recurrent, often fatal or disabling, cardioembolic stroke. We also describe the issues related to translating these interventions into practice and the related economic implications. Despite the proven effectiveness and cost–effectiveness of these and other interventions, many people experiencing stroke are not receiving these interventions. Effective evidence translation initiatives and routine monitoring of healthcare is needed to address important gaps in stroke management in promoting societal well-being.

Making the case for cost-effectiveness research

Cost-effectiveness research is a component of clinical outcomes that addresses both cost and outcomes simultaneously, providing an understanding of what incremental costs, if any, are required for better clinical outcomes. In the current health care climate, these analyses are increasingly performed, and critical, as practitioners must optimize patient care at lower costs. This review discusses cost effectiveness research, its utilization in surgical oncology, and future opportunities provided by its methodologies.

Potential impact of new oral anticoagulants on the management of atrial fibrillation-related stroke in primary care

AIM

Anticoagulant prophylaxis with vitamin K antagonists (such as warfarin) is effective in reducing the risk of stroke in patients with atrial fibrillation (AF). New oral anticoagulants have emerged as potential alternatives to traditional oral agents. The purpose of this review was to summarise the effectiveness and safety of rivaroxaban, dabigatran and apixaban in stroke prevention in patients with AF in phase III trials, evaluate their cost-effectiveness and consider the implications for primary care.

METHODOLOGY

A literature search was performed between 2007 and 2012, selecting all phase III trials (ROCKET AF, RE-LY and ARISTOTLE) of new oral anticoagulants and relevant cost-benefit studies.

RESULTS

Evidence shows that all three agents are at least as effective as warfarin in the prevention of stroke and systemic emboli, with similar safety profiles. Cost-benefit studies of rivaroxaban and dabigatran further confirm their potential use as alternatives to warfarin in clinical practice. These observations may allow stratification of the general practice AF population, to help prioritise which patients may benefit from receiving a new oral anticoagulant.

CONCLUSION

The clinical and economic benefits of the new oral anticoagulants, along with appropriate risk stratification, may enable a higher number of patients with AF to receive effective and convenient prophylaxis for stroke prevention.

Cost-effectiveness of pharmacogenetics in anticoagulation: international differences in healthcare systems and costs

Genotyping patients for CYP2C9 and VKORC1 polymorphisms can improve the accuracy of dosing during the initiation of anticoagulation with vitamin K antagonists (coumarin derivatives). The anticipated degree of improvement in the safety of anticoagulation with coumarins through genotyping may vary depending on the quality of patient care, which varies both with and among countries. The management and the cost of anticoagulant care can therefore influence the cost-effectiveness of genotyping within any given country. In this article, we provide an overview of the cost-effectiveness of pharmacogenetics-guided dosing of coumarin derivatives. We describe the organization of anticoagulant care in the UK, Sweden, The Netherlands, Greece, Germany and Austria, where a genotype-guided dosing algorithm is currently being investigated as part of the EU-PACT trial. We also explore the costs of anticoagulant care for the treatment of atrial fibrillation in these countries.

Modeling gradually changing seasonal variation in count data using state space models: a cohort study of hospitalization rates of stroke in atrial fibrillation patients in Denmark from 1977 to 2011

BACKGROUND

Seasonal variation in the occurrence of cardiovascular diseases has been recognized for decades. In particular, incidence rates of hospitalization with atrial fibrillation (AF) and stroke have shown to exhibit a seasonal variation. Stroke in AF patients is common and often severe. Obtaining a description of a possible seasonal variation in the occurrence of stroke in AF patients is crucial in clarifying risk factors for developing stroke and initiating prophylaxis treatment.

METHODS

Using a dynamic generalized linear model we were able to model gradually changing seasonal variation in hospitalization rates of stroke in AF patients from 1977 to 2011. The study population consisted of all Danes registered with a diagnosis of AF comprising 270,017 subjects. During follow-up, 39,632 subjects were hospitalized with stroke. Incidence rates of stroke in AF patients were analyzed assuming the seasonal variation being a sum of two sinusoids and a local linear trend.

RESULTS

The results showed that the peak-to-trough ratio decreased from 1.25 to 1.16 during the study period, and that the times of year for peak and trough changed slightly.

CONCLUSION

The present study indicates that using dynamic generalized linear models provides a flexible modeling approach for studying changes in seasonal variation of stroke in AF patients and yields plausible results.

The economics of atrial fibrillation: a time for review and prioritization

Stroke associated with atrial fibrillation may occur in up to one third of people who experience an ischemic event, and results in greater stroke severity and poorer health outcomes. The ageing population in developed and developing countries will lead to an increase in the prevalence of atrial fibrillation in society. Detecting people who have atrial fibrillation and ensuring optimal prevention management is essential for reducing the burden of stroke worldwide. There is evidence that use of anticoagulants is inadequate in primary and secondary prevention of stroke. New anticoagulants that have fewer side effects and population screening tools are available. However, there is little information available about the cost-effectiveness of these new options for atrial fibrillation detection and stroke prevention management over current practice. Since resources for spending in health are limited, it is essential that formal economic analyses are undertaken to ensure there are informed and evidence-based decisions on where to best invest stroke prevention resources. It is essential that renewed efforts in the area of atrial fibrillation and options for stroke prevention are undertaken within the public health research community.

A New Landscape for Stroke Prevention in Atrial Fibrillation

Background—

Worldwide, atrial fibrillation is the most common arrhythmia, and its symptoms and sequelae cause an enormous burden to patients and health systems. Stroke is associated with the greatest mortality and morbidity in patients with atrial fibrillation (AF). The last decade has seen great advances in scientific and therapeutic approaches to AF.

Purpose—

This review considers recent changes to stroke prevention, particularly focusing on new anticoagulants, antiarrhythmic drugs, and devices as well as future research directions.

Summary of Review—

A semi-systematic literature review was performed using search terms “atrial fibrillation” and “novel therapy” within the PubMed database from 2005 to 2011. The area of greatest progress has been novel anticoagulants with direct thrombin inhibitors and factor Xa inhibitors. Dabigatran is the only novel agent currently licensed for use in AF patients, but with several trials of novel agents pending and favorable results so far, other agents are likely to follow. Novel antiarrhythmic drugs, left atrial appendage occlusion, and upstream therapies all represent potential new approaches but require further research.

Conclusions—

Novel anticoagulant and arrhythmic agents are changing treatment guidelines and choices available to both patients and clinicians for stroke prevention in AF, but bring new considerations and long-term data are required, because most patients will require lifelong therapy. Future research must incorporate patient values and preferences, because novel therapies can potentially give very different treatment options, which must be explained for patients to make informed choices.