Estimated medical cost reductions associated with use of novel oral anticoagulants vs warfarin in a real-world non-valvular atrial fibrillation patient population

Comparative study of adverse drug reactions among direct-acting oral anticoagulants and vitamin K antagonists using the EudraVigilance database

Our aim was to compare adverse drug reactions (ADRs) associated with direct-acting oral anticoagulants and vitamin K antagonists from the European EudraVigilance (EV) database. The EV database is the system for the analysis of information on suspected ADRs that are authorised, or being evaluated in clinical trials, in the European Economic Area. Registered ADRs (from the groups "Gastrointestinal disorders", "General disorders and administration site conditions", "Injury, poisoning and procedural complications", "Nervous system (NS) disorders" and "Vascular disorders") for apixaban, rivaroxaban, dabigatran and vitamin K antagonists (VKA) were collected by age group (< 65 years; 65-85 years and > 85 years) and by sex. The proportional reporting ratio (PRR) was used to compare ADRs in relation to the anticoagulants tested. A total of 274,693 ADRs were analysed. For gastrointestinal ADRs, patients treated with rivaroxaban and dabigatran (PRR 2.17 and 2.51, respectively) were at significantly higher risks than those treated with apixaban and VKA (PRR 1.27 and 1.47, respectively), while risks for vascular disorders were increased by all anticoagulants that were tested. Lastly, none of the anticoagulants significantly increased the risk of ADRs within the NS group. Rivaroxaban and dabigatran were associated with a significantly higher risk of gastrointestinal ADR than apixaban or VKA. All anticoagulants increased the risk of vascular pathology while none of them demonstrated significant increased risk of ADR to NS.

Cost-Effectiveness of Extended and One-Time Screening Versus No Screening for Non-Valvular Atrial Fibrillation in the USA

BACKGROUND

There is limited evidence on the clinical and cost benefits of screening for atrial fibrillation (AF) with electrocardiogram (ECG) in asymptomatic adults.

METHODS

We adapted a previously published Markov model to evaluate the clinical and economic impact of one-time screening for non-valvular AF (NVAF) with a single 12-lead ECG and a 14-day extended screening with a hand-held ECG device (Zenicor single-lead ECG, Z14) compared with no screening. Clinical events considered included ischemic stroke, systemic embolism, major bleeds, myocardial infarction, and death. Epidemiology and effectiveness data for extended screening were from the STROKESTOP study. Risks of clinical events in NVAF patients were derived from ARISTOTLE. Analyses were conducted from the perspective of a third-party payer, considering a population with undiagnosed NVAF, aged 75 years in the USA. Costs and utilities were discounted at a 3% annual rate. Parameter uncertainty was formally considered via deterministic and probabilistic sensitivity analyses (DSA and PSA). Structural uncertainty was assessed via scenario analyses.

RESULTS

In a hypothetical cohort of 10,000 patients followed over their lifetimes, the number of additional AF diagnoses was 54 with 12-lead ECG and 255 with Z14 compared with no screening. Both screening strategies led to better health outcomes (ischemic strokes avoided: ECG 12-lead, 9.8 and Z14, 42.2; quality-adjusted life-years gained: ECG 12-lead, 31 and Z14, 131). Extended screening and one-time screening were cost effective compared with no screening at a willingness-to-pay (WTP) threshold of $100,000 per QALY gained ($58,728/QALY with ECG 12-lead and $47,949/QALY with Z14 in 2016 US dollars). ICERs remained below $100,000 per QALY in all DSA, most PSA runs, and in all scenario analyses except for a scenario assuming low anticoagulation persistence.

CONCLUSIONS

Our analysis suggests that, screening the general population at age 75 years for NVAF is cost effective at a WTP threshold of $100,000. Both extended screening and one-time screening for NVAF are expected to provide health benefits at an acceptable cost.

Clinical Characteristics And Health Care Resources In Patients Treated With Oral Anticoagulants: Evidences From Italian Administrative Databases

Objectives

1) To evaluate anticoagulation treatment patterns and health care resource use in adult patients with a discharge diagnosis of non-valvular atrial fibrillation (NVAF) in an Italian real-world setting and 2) to describe the characteristics of NVAF patients in relation to treatment.

Design

A retrospective cohort study in a "real-world" setting.

Setting

Data were analysed by integrating administrative databases that included approximately 2,000,000 individuals assisted by the National Health System from two Italian Local Health Units.

Participants

All adult patients with at least one hospital discharge or ≥2 outpatient visits with a diagnosis code for NVAF from 1/01/2011 to 31/12/2015 were included.

Main outcome measures

Anticoagulation treatment patterns, health care resource use and major bleeding events that occurred during the follow-up period were evaluated.

Results

32,863 NVAF patients were included, of whom 7,831 had at least one prescription of oral anticoagulants. Among them, 6,876 patients were vitamin K antagonists (VKA) users and 955 were non-vitamin K antagonist oral anticoagulant (NOAC) users at index date (ID). During the follow-up period, the use of antiplatelet drugs was higher among VKA-naïve users than the NOAC-naïve users. Among NOAC users, 76.1% showed an adherence level ≥80% during follow-up. The rate of bleeding events resulted higher for VKA patients compared to NOAC patients. The unadjusted incidence rate was 10.46 per 1000 person-year for VKA patients and 4.55 per 1,000 person-years for NOAC patients. The overall annual cost (in term of drugs, hospitalisations and outpatient specialist services) was € 5,156.13 for VKA and € 4,630.57 for NOAC.

Conclusion

This unselected cohort study, on NVAF patients being prescribed oral anticoagulants, highlights that VKA was largely prescribed and the great majority of patients on NOACs were adherent to treatment. Most of the OAC patients still received antiplatelet agents in combination, and in NOAC patients, we registered a lower number of bleeding events compared with VKA.

Time-driven activity-based cost analysis for outpatient anticoagulation therapy: direct costs in a primary care setting with optimal performance

OBJECTIVES

To determine how overall cost of anticoagulation therapy for warfarin compares with that of Novel Oral Anticoagulants (NOACs). Also, to demonstrate a scientific, comprehensive, and an analytical approach to estimate direct costs involved in monitoring and management of anticoagulation therapy for outpatients in an academic primary care clinic setting, post-initiation of therapy.

METHODS

A population-based cross-sectional study was conducted in conjunction with observations of patient care processes between August 2014 and January 2015. The study was conducted in an academic primary care outpatient setting at Mayo Clinic's warfarin anticoagulation clinic, Rochester, MN. The anticoagulation clinic serves patients 18 years of age or older in Warfarin therapy management, for any indication, after referral from the patient's primary care provider. The study included anticoagulation clinic enrollment data on a population of 5,526 patients. Time-Driven Activity-Based Costing (TDABC) technique was applied. Detailed process flow maps which showed process steps for all the anticoagulation program components and care continuum phases were created. Staff roles associated with each of the process steps were identified and displayed on the maps. Process times and costs were captured and analyzed. The main outcome was direct cost of monitoring and management of anticoagulation therapy, post-initiation of therapy.

RESULTS

The cost of warfarin management for patients who display unstable International Normalized Ratio (INR) is more than three times those who display stable INR over time. (Comparator to distinguish stability: Frequency of point-of-care visits needed by patients.) For complex anticoagulation patients, total cost of medication and monitoring for warfarin anticoagulation therapy is similar to that for NOACs.

CONCLUSION

Despite warfarin being significantly less expensive to purchase than NOACs, overall warfarin management incurs higher costs due to laboratory monitoring and provider time than NOACs. NOAC treatment, therefore, may not be more expensive than warfarin therapy management for complex anticoagulation patients.

A Survey on the Awareness and Attitude of Physicians on Direct Oral Anticoagulants in Qatar

Direct oral anticoagulants (DOACs) are more commonly prescribed since their introduction. Reports on inappropriate prescribing have been observed which may indicate poor awareness on these agents. In this study, we aim to evaluate the extent of the physicians' knowledge on DOACs and its possible impact on physicians' confidence to prescribe these medications. A prospective cross-sectional survey was developed based on the literature review. Eligible participants were physicians and surgeons currently practicing at Hamad General Hospital in Qatar. The survey included questions on demographic and professional characteristics. It also evaluated the awareness and attitudes regarding safety, efficacy, and prescribing of DOACs. Over 6-month period, 175 practitioners responded to the survey. Overall awareness score was moderate (61% ± 18%). These scores were in alignment with participants' self-satisfaction with knowledge on DOACs (66% were not satisfied) and participants' confidence toward prescribing DOACs (48% were not confident). Age, degree of education, and years of experience had significant positive influence on awareness score. This survey indicates that practitioners have moderate awareness on DOACs. Future work should focus on reassessing practitioners' knowledge after providing well-designed education campaigns.

Comparison of all-cause costs and healthcare resource use among patients with newly-diagnosed non-valvular atrial fibrillation newly treated with oral anticoagulants

OBJECTIVES

Compare costs and healthcare resource utilization (HCRU) among newly-diagnosed non-valvular atrial fibrillation (NVAF) patients newly treated with dabigatran vs apixaban, rivaroxaban, or warfarin.

METHODS

Newly-diagnosed adult NVAF patients initiating dabigatran, apixaban, rivaroxaban, or warfarin (index event) between October 1, 2010-December 31, 2014 were identified using MarketScan claims data, and followed until medication discontinuation, switch, inpatient death, enrollment end, or study end (December 31, 2015). Dabigatran patients were propensity-score matched 1:1 separately with apixaban, rivaroxaban, and warfarin patients. Per-patient-per-month (PPPM) all-cause cost, HCRU, and 30-day re-admissions were reported. Costs were analyzed using generalized linear models.

RESULTS

Final cohorts, each matched with dabigatran patients, included 8,857 apixaban patients, 26,592 rivaroxaban patients, and 33,046 warfarin patients. Dabigatran patients had lower adjusted PPPM total healthcare, inpatient, and outpatient costs compared to rivaroxaban ($4,093 vs $4,636, $1,476 vs $1,862, and $2,016 vs $2,121, respectively, all p ≤ .001) and warfarin ($4,199 vs $4,872, $1,505 vs $1,851, and $2,049 vs $2,514, respectively, all p < .001). Adjusted costs were similar for dabigatran and apixaban. Dabigatran patients had significantly fewer hospitalizations, outpatient visits, and pharmacy claims than rivaroxaban patients (0.06 vs 0.07, 4.84 vs 4.96 and 4.80 vs 4.93, respectively, all p < .020) and warfarin patients (0.06 vs 0.07, 4.77 vs 6.88, and 4.76 vs 5.89, respectively, all p < .001). Dabigatran patients had similar hospitalizations to apixaban, but higher outpatient visits (4.70 vs 4.31) and pharmacy claims (4.86 vs 4.61), both p < .001.

CONCLUSIONS

This real-world study found adjusted all-cause costs were lower for dabigatran compared to rivaroxaban and warfarin patients and similar to apixaban patients.

Setting priorities in the health care sector - the case of oral anticoagulants in nonvalvular atrial fibrillation in Denmark

Aim

Resources devoted to health care are limited, therefore setting priorities is required. It differs between countries whether decision-making concerning health care technologies focus on broad economic perspectives or whether focus is narrow on single budgets (“silo mentality”). The cost perspective as one part of the full health economic analysis is important for decision-making. With the case of oral anticoagulants in patients with nonvalvular atrial fibrillation (NVAF), the aim is to discuss the implication of the use of different cost perspectives for decision-making and priority setting.

Methods

In a cost analysis, the annual average total costs of five oral anticoagulants (warfarin and non-vitamin K oral anticoagulants [NOACs; dabigatran, rivaroxaban, apixaban, and edoxaban]) used in daily clinical practice in Denmark for the prevention of stroke in NVAF patients are analyzed. This is done in pairwise comparisons between warfarin and each NOAC based on five potential cost perspectives, from a “drug cost only” perspective up to a “societal” perspective.

Results

All comparisons of warfarin and NOACs show that the cost perspective based on all relevant costs, ie, total costs perspective, is essential for the choice of therapy. Focusing on the reimbursement costs of the drugs only, warfarin is the least costly option. However, with the aim of therapy to prevent strokes and limit bleedings, including the economic impact of this, all NOACs, except rivaroxaban, result in slightly lower health care costs compared with warfarin. The same picture was found applying the societal perspective.

Conclusion

Many broad cost-effectiveness analyses of NOACs exist. However, in countries with budget focus in decision-making this information does not apply. The present study’s case of oral anticoagulants has shown that decision-making should be based on health care or societal cost perspectives for optimal use of limited resources. Otherwise, the risk is that suboptimal decisions will be likely.

Risk of stroke/systemic embolism, major bleeding and associated costs in non-valvular atrial fibrillation patients who initiated apixaban, dabigatran or rivaroxaban compared with warfarin in the United States Medicare population

OBJECTIVE

To compare the risk and cost of stroke/systemic embolism (SE) and major bleeding between each direct oral anticoagulant (DOAC) and warfarin among non-valvular atrial fibrillation (NVAF) patients.

METHODS

Patients (≥65 years) initiating warfarin or DOACs (apixaban, rivaroxaban, and dabigatran) were selected from the Medicare database from 1 January 2013 to 31 December 2014. Patients initiating each DOAC were matched 1:1 to warfarin patients using propensity score matching to balance demographics and clinical characteristics. Cox proportional hazards models were used to estimate the risks of stroke/SE and major bleeding of each DOAC vs. warfarin. Two-part models were used to compare the stroke/SE- and major-bleeding-related medical costs between matched cohorts.

RESULTS

Of the 186,132 eligible patients, 20,803 apixaban-warfarin pairs, 52,476 rivaroxaban-warfarin pairs, and 16,731 dabigatran-warfarin pairs were matched. Apixaban (hazard ratio [HR] = 0.40; 95% confidence interval [CI] 0.31, 0.53) and rivaroxaban (HR = 0.72; 95% CI 0.63, 0.83) were significantly associated with lower risk of stroke/SE compared to warfarin. Apixaban (HR = 0.51; 95% CI 0.44, 0.58) and dabigatran (HR = 0.79; 95% CI 0.69, 0.91) were significantly associated with lower risk of major bleeding; rivaroxaban (HR = 1.17; 95% CI 1.10, 1.26) was significantly associated with higher risk of major bleeding compared to warfarin. Compared to warfarin, apixaban ($63 vs. $131) and rivaroxaban ($93 vs. $139) had significantly lower stroke/SE-related medical costs; apixaban ($292 vs. $529) and dabigatran ($369 vs. $450) had significantly lower major bleeding-related medical costs.

CONCLUSIONS

Among the DOACs in the study, only apixaban is associated with a significantly lower risk of stroke/SE and major bleeding and lower related medical costs compared to warfarin.

DOACs - advances and limitations in real world

The group of new oral anticoagulants or NOACs, now termed direct oral anticoagulants or DOACs, with their favourable results from large scale phase III clinical trials, represent a major advancement and expanded armamentarium in antithrombotic therapy. Dabigatran, rivaroxaban, apixaban and edoxaban are now in clinical routine use for prevention and treatment of arterial and venous thrombotic diseases as addressed in their clinical trials. Usage of the DOACs is expected to increase as clinicians gain more experience and reassurance with data from the real world studies which are generally consistent with that from clinical trials. Development of specific antidotes in management of bleeding complications and development of coagulation assays for their plasma levels will further boost the confidence in the DOACs. Nonetheless, there are still limitations associated with the DOACs. Many patients in need of anticoagulant therapy for indications not studied in the clinical trials will not be eligible for treatment with a DOAC. Conditions where more data is required include DOACs use in the paediatric age group, patients with atrial fibrillation and valvular heart disease, thrombosis associated with the anti-phospholipid syndrome and cancer associated thrombosis. The affordability and access to these drugs may pose an issue for many patients under healthcare systems not providing for these medications. With four new anticoagulants coming onboard very quickly, the focus has shifted to the practical approach and management in real life as many clinicians are not yet familiar with the DOACs. Clinicians need to be educated on how to manage this new class for drugs, from choosing the appropriate drug to prevention and managing bleeding complications as a lack of knowledge and understanding in these drugs will lead to inappropriate use and compromise on patient safety.

Does novel oral anticoagulant improve anticoagulation for non-valvular atrial fibrillation associated stroke: An inpatient registration study in Shanghai

OBJECTIVE

To summarize the use rate, safety, efficacy of antithrombotics in stroke/transient ischemic attack (TIA) prevention, and reasons for not using dabigatran etexilate (DE) in Shanghai, China.

METHODS

Non-valvular atrial fibrillation (NVAF)-associated stroke patients were prospectively registered as an electronic database. Use rate of antithrombotics and reasons for not using DE were extracted during follow-up. Patients' baseline characteristics, recurrent ischemic stroke/TIA events and bleeding complications were analyzed.

PATIENTS

From April 2012 to August 2014, 110 inpatients with NVAF-associated stroke were studied in our hospital. NVAF was diagnosed by 12-lead electrocardiogram, 24 h Holter and echocardiography.

RESULTS

Before introduction of DE (April 2013), use rates of warfarin and antiplatelets were 28.9% (11/38) and 60.5% (23/38) respectively; after that, use rates of warfarin, DE, and antiplatelets were 20.8% (15/72), 12.5% (9/72), and 43.1% (31/72). The DE did not improve use of anticoagulants (P = 0.639). There were 19 (17.3%) recurrent ischemic stroke events up to October 2015; two (9.5%) in the non-user group, 10 (18.5%) in the antiplatelet group, and seven (20.0%) in the anticoagulants group (P = 0.570). Furthermore, recurrence rates were similar between the DE group (20.0%) and the Warfarin group (20.0%, P = 1.000). The most common reason for not using DE was financial concerns (61.0%), followed by inconvenience to purchase (14.0%) and hemorrhage concerns (11.0%). Two patients using warfarin found fecal occult blood so they stopped warfarin and began to use antiplatelet drugs. No bleeding event occurred in the other groups. Only one patient had side effects (dyspepsia and gastroesophageal reflux) from DE.

CONCLUSION

The use rate of either DE or warfarin in Shanghai was low; DE had not improved anticoagulation therapy for NVAF patients in Shanghai mainly because DE had not been covered by health insurance.

New oral anticoagulants for patients with nonvalvular atrial fibrillation

Four new oral anticoagulants have been approved for reducing stroke risk in patients with nonvalvular atrial fibrillation. Compared with warfarin, these agents offer a more predictable dose response with fewer food and drug interactions and no regular blood monitoring, although some of the drugs have an increased risk of major gastrointestinal bleeding. This article reviews the new drugs.