Cost-effectiveness of dabigatran and rivaroxaban compared with warfarin for stroke prevention in patients with atrial fibrillation.

PURPOSE: This study aimed to evaluate the cost-effectiveness of dabigatran and rivaroxaban compared with warfarin for the prevention of stroke in patients with atrial fibrillation (AF) in Singapore. METHODS: A Markov model was constructed to compare the lifetime costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) of dabigatran 110 and 150 mg, rivaroxaban 20 mg and adjusted-dose warfarin from the perspective of the Singapore healthcare system, using clinical data from published studies, utilities from a patient-reported survey and costs from hospital databases. The target population was a hypothetical cohort of 65-year-old AF patients with no contraindications to anticoagulation. RESULTS: In the base-case analysis, the QALYs were 8.75 with warfarin, 8.73 with dabigatran 110 mg, 8.82 with dabigatran 150 mg, and 9.33 with rivaroxaban. The costs were Singapore dollar (SG$) 34,648 for warfarin, SG$54,919 for dabigatran 110 mg, SG$50,484 for dabigatran 150 mg and SG$51,975 for rivaroxaban. The ICER of rivaroxaban versus warfarin was SG$29,697 (US$26,727) per QALY. Rivaroxaban and warfarin had extended dominance over the high-dose dabigatran. The low-dose dabigatran was dominated by warfarin. Deterministic sensitivity analyses showed that the ICER of rivaroxaban versus warfarin was sensitive to cost of rivaroxaban and utilities for rivaroxaban and warfarin. Probability sensitivity analysis demonstrated that the probability of rivaroxaban being the optimal choice was 97.8% and 99.5% at a willingness-to-pay threshold of SG$65,000 (US$58,500) and SG$130,000 (US$117,000) per QALY, respectively. CONCLUSION: Rivaroxaban may be a cost-effective alternative to warfarin for the prevention of stroke in patients with AF in Singapore.

Cost effectiveness of new oral anticoagulants for stroke prevention in patients with atrial fibrillation in two different European healthcare settings.

OBJECTIVES: Our objectives were to investigate the cost effectiveness of apixaban, rivaroxaban, and dabigatran compared with coumarin derivatives for stroke prevention in patients with atrial fibrillation in a country with specialized anticoagulation clinics (the Netherlands) and in a country without these clinics (the UK). METHODS: A decision-analytic Markov model was used to analyse the cost effectiveness of apixaban, rivaroxaban, and dabigatran compared with coumarin derivatives in the Netherlands and the UK over a lifetime horizon. RESULTS: In the Netherlands, the use of rivaroxaban, apixaban, or dabigatran increased health by 0.166, 0.365, and 0.374 quality-adjusted life-years (QALYs) compared with coumarin derivatives, but also increased costs by 5,681, 4,754, and 5,465, respectively. The incremental cost-effectiveness ratios (ICERs) were 34,248, 13,024, and 14,626 per QALY gained. In the UK, health was increased by 0.302, 0.455, and 0.461 QALYs, and the incremental costs were similar for all three new oral anticoagulants (5,118-5,217). The ICERs varied from 11,172 to 16,949 per QALY gained. In the Netherlands, apixaban had the highest chance (37 %) of being cost effective at a threshold of 20,000; in the UK, this chance was 41 % for dabigatran. The quality of care, reflected in time in therapeutic range, had an important influence on the ICER. CONCLUSIONS: Apixaban, rivaroxaban, and dabigatran are cost-effective alternatives to coumarin derivatives in the UK, while in the Netherlands, only apixaban and dabigatran could be considered cost effective. The cost effectiveness of the new oral anticoagulants is largely dependent on the setting and quality of local anticoagulant care facilities.

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

OBJECTIVE: This study evaluated differences in medical costs associated with clinical end-points from randomized clinical trials that compared the new oral anticoagulants (NOACs), dabigatran, rivaroxaban, apixaban, and edoxaban, to standard therapy for treatment of patients with venous thromboembolism (VTE). RESEARCH DESIGN AND METHODS: Event rates of efficacy and safety end-points from the clinical trials (RE-COVER, RE-COVER II, EINSTEIN-Pooled, AMPLIFY, Hokusai-VTE trial) were obtained from published literature. Incremental annual medical costs among patients with clinical events from a US payer perspective were obtained from the literature or healthcare claims databases and inflation adjusted to 2013 costs. Differences in total medical costs associated with clinical end-points for the NOACs vs standard therapy were then estimated. One-way and Monte Carlo sensitivity analyses were carried out. RESULTS: A lower rate of major bleedings was associated with use of any of the NOACs vs standard therapy. Except for dabigatran, use of NOACs was also associated with a lower rate of recurrent VTE/death. As a result of the reduction in clinical event rates, the overall medical cost differences were -$146, -$482, -$918, and -$344 for VTE patients treated with dabigatran, rivaroxaban, apixaban, and edoxaban, respectively, vs patients treated with standard therapy. CONCLUSIONS: When any of the four NOACs are used instead of standard therapy for acute VTE, treatment medical costs are reduced. Apixaban is associated with the greatest reduction in medical costs, which is driven by medical cost reductions associated with both efficacy and safety end-points. Further evaluation may be needed to validate these results in the real-world setting.

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

OBJECTIVE: RESULTS of randomized clinical trials (RCT) demonstrate that novel oral anticoagulants (NOAC) are effective therapies for reducing the risk of stroke in non-valvular atrial fibrillation (NVAF). Prior medical cost avoidance studies have used warfarin event rates from RCTs, which may differ from patients receiving treatment in a real-world (RW) setting, where the quality of care may not be the same as in a RCT. The purpose of this study was to estimate the change in medical costs related to stroke and major bleeding for each NOAC (apixaban, dabigatran, and rivoraxaban) relative to warfarin in a RW NVAF population. METHODS: Patients (n = 23,525) with a diagnosis of NVAF during 2007-2010 were selected from a Medco population of US health plans. Stroke and major bleeding excluding intracranial hemorrhage (MBEIH) events were identified using diagnosis codes on medical claims. RW reference event rates were calculated during periods of warfarin exposure. RW event rates for NOACs were estimated by multiplying the corresponding relative risk (RR) from the RCTs by each reference rate. Absolute risk reductions (ARR) or number of events avoided per patient year were then estimated. Changes in medical costs associated with each NOAC were calculated by applying the ARR to the 1-year cost for each event. Costs for stroke and MBEIH were obtained from the literature. Drug and international normalized ratio monitoring costs were not considered in this analysis. RESULTS: Compared to RW warfarin, use of apixaban and dabigatran resulted in total (stroke plus MBEIH) medical cost reductions of $1245 and $555, respectively, during a patient year. Rivaroxaban resulted in a medical cost increase of $144. CONCLUSIONS: If relative risk reductions demonstrated in RCTs persist in a RW setting, apixaban would confer the greatest medical cost savings vs warfarin, resulting from significantly lower rates of both stroke and MBEIH.

Patterns of initiation of oral anticoagulants in patients with atrial fibrillation- quality and cost implications.

BACKGROUND: Dabigatran, rivaroxaban, and apixaban have been approved for use in patients with atrial fibrillation based upon randomized trials demonstrating their comparable or superior efficacy and safety relative to warfarin. Little is known about their adoption into clinical practice, whether utilization is consistent with the controlled trials on which their approval was based, and how their use has affected health spending for patients and insurers. METHODS: We used medical and prescription claims data from a large insurer to identify patients with nonvalvular atrial fibrillation who were prescribed an oral anticoagulant in 2010-2013. We plotted trends in medication initiation over time, assessed corresponding insurer and patient out-of-pocket spending, and evaluated the cumulative number and cost of anticoagulants. We identified predictors of novel anticoagulant initiation using multivariable logistic models. Finally, we estimated the difference in total drug expenditures over 6 months for patients initiating warfarin versus a novel anticoagulant. RESULTS: There were 6893 patients with atrial fibrillation that initiated an oral anticoagulant during the study period. By the end of the study period, novel anticoagulants accounted for 62% of new prescriptions and 98% of anticoagulant-related drug costs. Female sex, lower household income, and higher CHADS2, CHA2DS2-VASC, and HAS-BLED scores were significantly associated with lower odds of receiving a novel anticoagulant (P <.001 for each). Average combined patient and insurer anticoagulant spending in the first 6 months after initiation was more than $900 greater for patients initiating a novel anticoagulant. CONCLUSIONS: This study demonstrates rapid adoption of novel anticoagulants into clinical practice, particularly among patients with lower CHADS2 and HAS-BLED scores, and high health care cost consequences. These findings provide important directions for future comparative and cost-effectiveness research.

Cost-effectiveness of apixaban versus other new oral anticoagulants for stroke prevention in atrial fibrillation.

BACKGROUND: Apixaban (5 mg BID), dabigatran (available as 150 mg and 110 mg BID in Europe), and rivaroxaban (20 mg once daily) are 3 novel oral anticoagulants (NOACs) currently approved for stroke prevention in patients with atrial fibrillation (AF). OBJECTIVE: The objective of this study was to evaluate the cost-effectiveness of apixaban against other NOACs from the perspective of the United Kingdom National Health Services. METHODS: A Markov model was developed to evaluate the pharmacoeconomic impact of apixaban versus other NOACs over a lifetime. Pair-wise indirect treatment comparisons were conducted against other NOACs by using ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation), RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy), and ROCKET-AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) trial results for the following end points: ischemic stroke, hemorrhagic stroke, intracranial hemorrhage, other major bleeds, clinically relevant nonmajor bleeds, myocardial infarction, and treatment discontinuations. Outcomes were life-years, quality-adjusted life years gained, direct health care costs, and incremental cost-effectiveness ratios. RESULTS: Apixaban was projected to increase life expectancy versus other NOACs, including dabigatran (both doses) and rivaroxaban. A small increase in therapeutic management costs was observed with apixaban due to projected gains in life expectancy and lower discontinuation rates anticipated on apixaban versus other NOACs through lifetime. The estimated incremental cost-effectiveness ratio was £9611, £4497, and £5305 per quality-adjusted life-year gained with apixaban compared with dabigatran 150 mg BID, dabigatran 110 mg BID, and rivaroxaban 20 mg once daily, respectively. Sensitivity analyses indicated that results were robust over a wide range of inputs. CONCLUSIONS: Although our analysis was limited by the absence of head-to-head trials, based on the indirect comparison data available, our model projects that apixaban may be a cost-effective alternative to dabigatran 150 mg BID, dabigatran 110 mg BID, and rivaroxaban 20 mg once daily for stroke prevention in AF patients from the perspective of the United Kingdom National Health Services.

Apixaban, dabigatran, and rivaroxaban versus warfarin for stroke prevention in non-valvular atrial fibrillation: a cost-effectiveness analysis.

BACKGROUND AND OBJECTIVE: Non-valvular atrial fibrillation (NVAF) increases the risk of systemic thromboembolic events; therefore, anticoagulant treatment with vitamin K antagonists is widely prescribed. Recently, new oral anticoagulants (NOAs) directly inhibiting thrombin (dabigatran) or factor Xa (rivaroxaban and apixaban) demonstrated their non-inferiority with respect to warfarin in reducing the thromboembolic risk. The aim of this study was to estimate the cost effectiveness of NOAs in an Italian setting. METHODS: A Markov decision model including ten health states and death was developed, and a 3-month Markov cycle and lifetime horizon were adopted. Transition probabilities and quality of life were estimated from three randomized trials and from additional reports in the literature. Analysis was performed in the context of the Italian National Health System. First- and second-order sensitivity analyses were made to test the robustness of the results. The mean European cost of dabigatran (2.58/day) was assigned to each NOA. RESULTS: The incremental cost-utility ratio was below 25,000/quality-adjusted life-year (QALY) gained for each NOA and each CHADS2 level, but differences among drugs were found. This result was sensitive to the time in (warfarin) therapeutic range and time horizon. CONCLUSIONS: Our analysis suggests that NOAs are a cost-effective treatment for the prevention of stroke in patients with NVAF in the Italian healthcare setting.

Cost-effectiveness of pharmacogenetics-guided warfarin therapy vs. alternative anticoagulation in atrial fibrillation.

Pharmacogenetics-guided warfarin dosing is an alternative to standard clinical algorithms and new oral anticoagulants for patients with nonvalvular atrial fibrillation. However, clinical evidence for pharmacogenetics-guided warfarin dosing is limited to intermediary outcomes, and consequently, there is a lack of information on the cost-effectiveness of anticoagulation treatment options. A clinical trial simulation of S-warfarin was used to predict times within therapeutic range for different dosing algorithms. Relative risks of clinical events, obtained from a meta-analysis of trials linking times within therapeutic range with outcomes, served as inputs to an economic analysis. Neither dabigatran nor rivaroxaban were cost-effective options. Along the cost-effectiveness frontier, in relation to clinically dosed warfarin, pharmacogenetics-guided warfarin and apixaban had incremental cost-effectiveness ratios of £13,226 and £20,671 per quality-adjusted life year gained, respectively. On the basis of our simulations, apixaban appears to be the most cost-effective treatment.

Cost-effectiveness of oral anticoagulants for treatment of atrial fibrillation.

BACKGROUND: New anticoagulants may improve health outcomes in patients with atrial fibrillation, but it is unclear whether their use is cost-effective. METHODS AND RESULTS: A Markov state transition was created to compare 4 therapies: dabigatran 150 mg BID, apixaban 5 mg BID, rivaroxaban 20 mg QD, and warfarin therapy. The population included those with newly diagnosed atrial fibrillation who were eligible for treatment with warfarin. Compared with warfarin, apixaban, rivaroxaban, and dabigatran, costs were $93 063, $111 465, and $140 557 per additional quality-adjusted life year gained, respectively. At a threshold of $100 000 per quality-adjusted life year, apixaban provided the greatest absolute benefit while still being cost-effective, although warfarin would be superior if apixaban was 2% less effective than expected. Although apixaban was the optimal strategy in our base case, in probabilistic sensitivity analysis, warfarin was optimal in an equal number of iterations at a cost-effectiveness threshold of $100 000 per quality-adjusted life year. CONCLUSIONS: While at a standard cost-effectiveness threshold of $100 000 per quality-adjusted life year, apixaban seems to be the optimal anticoagulation strategy; this finding is sensitive to assumptions about its efficacy and cost. In sensitivity analysis, warfarin seems to be the optimal choice in an equal number of simulations. As a result, although all the novel oral anticoagulants produce greater quality-adjusted life expectancy than warfarin, they may not represent good value for money.

Cost-effectiveness of new oral anticoagulants compared with warfarin in preventing stroke and other cardiovascular events in patients with atrial fibrillation.

OBJECTIVES: The primary objective was to assess the cost-effectiveness of new oral anticoagulants compared with warfarin in patients with nonvalvular atrial fibrillation. Secondary objectives related to assessing the cost-effectiveness of new oral anticoagulants stratified by center-specific time in therapeutic range, age, and CHADS2 score. METHODS: Cost-effectiveness was assessed by the incremental cost per quality-adjusted life-year (QALY) gained. Analysis used a Markov cohort model that followed patients from initiation of pharmacotherapy to death. Transition probabilities were obtained from a concurrent network meta-analysis. Utility values and costs were obtained from published data. Numerous deterministic sensitivity analyses and probabilistic analysis were conducted. RESULTS: The incremental cost per QALY gained for dabigatran 150 mg versus warfarin was $20,797. Apixaban produced equal QALYs at a higher cost. Dabigatran 110 mg and rivaroxaban were dominated by dabigatran 150 mg and apixaban. Results were sensitive to the drug costs of apixaban, the time horizon adopted, and the consequences from major and minor bleeds with dabigatran. Results varied by a center's average time in therapeutic range, a patient's CHADS2 score, and patient age, with either dabigatran 150 mg or apixaban being optimal. CONCLUSIONS: Results were highly sensitive to patient characteristics. Rivaroxaban and dabigatran 110 mg were unlikely to be cost-effective. For different characteristics, apixaban or dabigatran 150 mg were optimal. Thus, the choice between these two options may come down to the price of apixaban and further evidence on the impact of major and minor bleeds with dabigatran.

New anticoagulants as thromboprophylaxis after total hip or knee replacement.

OBJECTIVES: Due to a high risk of thromboembolism in patients undergoing major orthopedic surgery, it has become standard practice to give thromboprophylactic treatment. We assessed the relative efficacy and cost-effectiveness of two new oral anticoagulants, rivaroxaban and dabigatran, relative to subcutaneous enoxaparin for the prevention of thromboembolism after total hip replacement (THR) and total knee replacement surgery (TKR). METHODS: We conducted a systematic review of the literature to assess efficacy and safety, and evaluated quality of documentation using GRADE. Cost-effectiveness was assessed by developing a decision model. The model combined two modules; a decision tree for the short-term prophylaxis and a Markov model for the long-term complications and survival gain. RESULTS: For rivaroxaban compared with enoxaparin, we found statistically significant decreases in deep vein thrombosis, but also a trend toward increased risk of major bleeding. For mortality and pulmonary embolism there were no statistically significant differences between the treatments. We did not find statistically significant differences between dabigatran and enoxaparin for our efficacy and safety outcomes. Assuming a willingness to pay of EUR62,500 per QALY, rivaroxaban following THR had a probability of 38 percent, and enoxaparin following TKR had a probability of 34 percent of being cost-effective. Clinical efficacy had the greatest impact on decision uncertainty. CONCLUSIONS: Dabigatran and rivaroxaban are comparable with enoxaparin following THR and TKR regarding the efficacy and safety outcomes. However, there is great uncertainty regarding which strategy is the most cost-effective. More research on clinical efficacy of rivaroxaban and dabigatran is likely to change our results.

A clinical decision aid for the selection of antithrombotic therapy for the prevention of stroke due to atrial fibrillation.

AIMS: The availability of new antithrombotic agents, each with a unique efficacy and bleeding profile, has introduced a considerable amount of clinical uncertainty with physicians. We have developed a clinical decision aid in order to assist clinicians in determining an optimal antithrombotic regime for the prevention of stroke in patients who are newly diagnosed with non-valvular atrial fibrillation. METHODS AND RESULTS: The CHA(2)DS(2)-VASc and HAS-BLED scoring systems were used to assess patients' baseline risks of stroke and major bleeding, respectively. The relative risks of stroke and major bleeding for each antithrombotic agent were then used to identify the agent associated with the lowest net risk. Individual patient factors such as the treatment threshold, bleeding ratio, and cost threshold modified the recommendations in order to generate a final recommendation. By considering both patient factors and clinical research concurrently, this clinical decision aid is able to provide specific advice to clinicians regarding an optimal stroke prevention strategy. The resulting treatment recommendation tables are consistent with the recommendations of the European Society of Cardiology and Canadian Cardiovascular Society Guidelines, which can be incorporated into either a paper-based or electronic format to allow clinicians to have decision support at the point of care. CONCLUSION: The use of a clinical decision aid that considers both patient factors and evidence-based medicine will serve to bridge the knowledge gap and provide practical guidance to clinicians in the prevention of stroke due to atrial fibrillation.

Anticoagulation prophylaxis in orthopedic surgery: an efficiency frontier approach.

UNLABELLED: This study assesses the use of new anticoagulants for the prevention of venous thromboembolism (VTE) in patients undergoing elective orthopedic surgery using traditional cost-effectiveness analysis and efficiency frontier methodology. RATIONALE: Efficiency frontier methodology has the potential to systematically improve the information used in policy and decision making, though it is still relatively uncommon in health economics. Anticoagulation in elective orthopedic surgery provides a fitting and timely case study for examining the influence of choosing one methodology over another. METHODS: An economic model was developed to capture the relative benefits and consequences of choosing one anticoagulation strategy over another in the context of orthopedic surgery. Three novel oral anticoagulants (apixaban, rivaroxaban, dabigatran) are compared with enoxaparin 40 mg daily from the UK National Health Service perspective using traditional cost-effectiveness estimates (cost/quality-adjusted life years, cost/life years gained) and the efficiency frontier. The latter explicitly includes embolic and bleeding events as outcomes. A 5-year time horizon was adopted. RESULTS: Total discounted costs ranged from about £200 000 to £431 000 over 5 years per 1000 patients undergoing elective total hip arthroplasty, and from £243 000 to £463 000 per 1000 patients for elective total knee arthroplasty. Analysis of the efficiency frontier demonstrates that apixaban and rivaroxaban are the preferred choices, depending on the outcome examined and the type of surgery. In terms of safety, apixaban is associated with more bleeding events avoided; yet, rivaroxaban demonstrated better VTE outcomes. CONCLUSION: Traditional cost-effectiveness analysis systematically excludes information related to the safety profiles of these anticoagulants. The efficiency frontier approach presented in this study provides critical information, without substantial effort, to permit a fully informed decision by taking into account all relevant outcomes as they relate to the costs associated with treatment choice.

Is dabigatran cost effective compared with warfarin for stroke prevention in atrial fibrillation? A critically appraised topic.

BACKGROUND: Warfarin has provided protection against cardioembolic stroke in the setting of nonvalvular atrial fibrillation (NVAF) for the past 60 years. Dabigatran, the first oral direct thrombin inhibitor to be approved in the United States, promises to provide the same or better stroke protection with reduced risk of intracranial hemorrhage. However, it remains to be seen whether grand-scale adoption of dabigatran will be cost effective. OBJECTIVE: To critically assess current evidence regarding the cost effectiveness of dabigatran for preventing stroke in patients with NVAF compared with warfarin. METHODS: The objective was addressed through the development of a critically appraised topic that included a clinical scenario, structured question, literature search strategy, critical appraisal, assessment of results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and resident neurologists, a medical librarian, clinical epidemiologists, and content experts in the field of vascular neurology. RESULTS: A cost-effectiveness analysis (CEA) that followed a hypothetical cohort of NVAF patients 65 years of age or older and CHADS2≥1 over their lifetime comparing dabigatran with adjusted-dose warfarin was reviewed. Assuming a willingness to pay a threshold of $50,000 per quality-adjusted life year (QALY), base case results favored high-dose (150 mg bid) dabigatran as a cost-effective alternative to warfarin. Sensitivity analysis asserted that the cost effectiveness of dabigatran improved if it could be obtained for ≤$13/d or if it was used in populations with high risk of stroke or intracranial hemorrhage. CONCLUSIONS: Dabigatran 150 mg bid ($12,286 per QALY) is a cost-effective alternative to International Normalized Ratio-adjusted warfarin for the prevention of ischemic stroke in patients 65 years of age or older with NVAF.

[Budgetary impact for the National Health System of apixaban prophylaxis of venous thromboembolism in patients undergoing total knee or hip replacement]. / Impacto presupuestario para el Sistema Nacional de Salud de la prevención del trombolismo venoso con apixaban en pacientes sometidos a artroplastia total de rodilla o cadera.

BACKGROUND: Due to high health care costs of venous thromboembolism (VTE), economic analyses are needed to determine the efficiency of different drug treatments. Consequently, a study was conducted to estimate the budgetary impact for the National Health System (NHS) with apixaban for prevention of venous thromboembolism (VTE) in total hip (THR) or knee (TKR) replacement. METHODS: Cost considered: the drugs for the prevention of VTE (apixaban, dabigatran, enoxaparin, fondaparinux, other heparins, rivaroxaban and warfarin) and the complications of VTE in the short term and in 5 years (deep vein thrombosis, pulmonary embolism, bleedings and the post-thrombotic syndrome). The effectiveness of prophylaxis was estimated using a meta-analysis. The VTE rates and death with apixaban are lower in THR and TKR than enoxaparin (-3.5% and -10.0%, respectively) with less bleeding events (-0.7% and -1.6%, respectively). Population data and unit costs were obtained from Spanish sources. TIME HORIZON: 5 years. All costs were discounted by 3.5% annually. Five years after commercialization, the use of apixaban was estimated to account for 23% of the prophylaxis of VTE and the use of enoxaparin decrease from the 60% to 33%. RESULTS: Apixaban´s introduction for the prophylaxis of VTE would have a significant impact for the NHS, resulting in a saving of 547,422 Euro over a period of 5 years. In the case of outpatient administration of heparin did not have a cost, the savings for the NHS five years amount to 270,068 Euro. CONCLUSIONS: According to this study, the introduction of apixaban may reduce the rate of VTE and bleeding compared with enoxaparin, decreasing the expenditure of NHS in VTE prophylaxis.

Characteristics of novel anticoagulants and potential economic implications.

Deep vein thrombosis and pulmonary embolism-the components of venous thromboembolism (VTE)-are significant causes of morbidity and mortality and are a major burden on US healthcare systems. Current VTE prevention strategies are often suboptimal after total hip or total knee arthroplasty, possibly due to drawbacks of the established anticoagulants, resulting in residual VTE and associated (or related) costs of care. New anticoagulant agents under development may address some of the limitations of current options and possibly increase adherence to guidelines for thromboprophylaxis. This article will review the characteristics of the new oral anticoagulants, which may potentially translate into cost savings for the healthcare system.

An indirect comparison, via enoxaparin, of rivaroxaban with dabigatran in the prevention of venous thromboembolism after hip or knee replacement.

OBJECTIVE: To compare the efficacy, in the prevention of venous thromboembolism (VTE), and safety, of rivaroxaban and dabigatran relative to the common comparator enoxaparin. METHODS: Two randomized clinical trials of dabigatran, one after total hip replacement (THR), RE-NOVATE, and one after total knee replacement (TKR), RE-MODEL, were identified as using the same enoxaparin regimen (40 mg once daily given the evening before surgery) and being of comparable duration to two rivaroxaban trials, RECORD1 and RECORD3. Indirect comparisons were performed on both efficacy and safety endpoints. To enable comparisons, symptomatic VTE results were based on the total study duration period, i.e. including the follow-up period. Major bleeding included surgical-site bleeding events. RESULTS: After THR, rivaroxaban 10 mg once daily significantly reduced total VTE and symptomatic VTE relative to dabigatran 220 mg once daily (relative risk 0.34 and 0.19, respectively). After TKR, rivaroxaban significantly reduced total VTE versus dabigatran (relative risk 0.53); symptomatic VTE was not different between dabigatran and rivaroxaban. There was no significant difference in the rates of major bleeding for patients receiving rivaroxaban or dabigatran. CONCLUSIONS: Based on the indirect comparisons, rivaroxaban was estimated to be more efficacious than dabigatran in the prevention of total VTE after THR and TKR. Our analysis relied upon published data for dabigatran and did not have the advantages of more detailed comparative data obtained directly from a randomized trial, as was the case with rivaroxaban. Further comparative research may be of value, but until available our conclusions represent the best available evidence.

Cost-effectiveness of dabigatran compared with warfarin for stroke prevention in atrial fibrillation.

BACKGROUND: Warfarin reduces the risk for ischemic stroke in patients with atrial fibrillation (AF) but increases the risk for hemorrhage. Dabigatran is a fixed-dose, oral direct thrombin inhibitor with similar or reduced rates of ischemic stroke and intracranial hemorrhage in patients with AF compared with those of warfarin. OBJECTIVE: To estimate the quality-adjusted survival, costs, and cost-effectiveness of dabigatran compared with adjusted-dose warfarin for preventing ischemic stroke in patients 65 years or older with nonvalvular AF. DESIGN: Markov decision model. DATA SOURCES: The RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial and other published studies of anticoagulation. The cost of dabigatran was estimated on the basis of pricing in the United Kingdom. TARGET POPULATION: Patients aged 65 years or older with nonvalvular AF and risk factors for stroke (CHADS2 score ≥1 or equivalent) and no contraindications to anticoagulation. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTION: Warfarin anticoagulation (target international normalized ratio, 2.0 to 3.0); dabigatran, 110 mg twice daily (low dose); and dabigatran, 150 mg twice daily (high dose). OUTCOME MEASURES: Quality-adjusted life-years (QALYs), costs (in 2008 U.S. dollars), and incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: The quality-adjusted life expectancy was 10.28 QALYs with warfarin, 10.70 QALYs with low-dose dabigatran, and 10.84 QALYs with high-dose dabigatran. Total costs were $143 193 for warfarin, $164 576 for low-dose dabigatran, and $168 398 for high-dose dabigatran. The incremental cost-effectiveness ratios compared with warfarin were $51 229 per QALY for low-dose dabigatran and $45 372 per QALY for high-dose dabigatran. RESULTS OF SENSITIVITY ANALYSIS: The model was sensitive to the cost of dabigatran but was relatively insensitive to other model inputs. The incremental cost-effectiveness ratio increased to $50 000 per QALY at a cost of $13.70 per day for high-dose dabigatran but remained less than $85 000 per QALY over the full range of model inputs evaluated. The cost-effectiveness of high-dose dabigatran improved with increasing risk for stroke and intracranial hemorrhage. LIMITATION: Event rates were largely derived from a single randomized clinical trial and extrapolated to a 35-year time frame from clinical trials with approximately 2-year follow-up. CONCLUSION: In patients aged 65 years or older with nonvalvular AF at increased risk for stroke (CHADS2 score ≥1 or equivalent), dabigatran may be a cost-effective alternative to warfarin depending on pricing in the United States. PRIMARY FUNDING SOURCE: American Heart Association and Veterans Affairs Health Services Research & Development Service.