Medical cost reductions associated with the usage of novel oral anticoagulants vs warfarin among atrial fibrillation patients,based on the RE-LY,ROCKET-AF,and ARISTOTLE trials

Abstract

Objective:

The randomized clinical trials, RE-LY, ROCKET-AF, and ARISTOTLE, demonstrate that the novel oral anticoagulants (NOACs) are effective options for stroke prevention among non-valvular atrial fibrillation (AF) patients. This study aimed to evaluate the medical cost reductions associated with the use of individual NOACs instead of warfarin from the US payer perspective.

Methods:

Rates for efficacy and safety clinical events for warfarin were estimated as the weighted averages from the RE-LY, ROCKET-AF and ARISTOTLE trials, and event rates for NOACs were determined by applying trial hazard ratios or relative risk ratios to such weighted averages. Incremental medical costs to a US health payer of an AF patient experiencing a clinical event during 1 year following the event were obtained from published literature and inflation adjusted to 2010 cost levels. Medical costs, excluding drug costs, were evaluated and compared for each NOAC vs warfarin. Sensitivity analyses were conducted to determine the influence of variations in clinical event rates and incremental costs on the medical cost reduction.

Results:

In a patient year, the medical cost reduction associated with NOAC usage instead of warfarin was estimated to be ?$179, ?$89, and ?$485 for dabigatran, rivaroxaban, and apixaban, respectively. When clinical event rates and costs were allowed to vary simultaneously, through a Monte Carlo simulation, the 95% confidence interval of annual medical costs differences ranged between ?$424 and +$71 for dabigatran, ?$301 and +$135 for rivaroxaban, and ?$741 and ?$252 for apixaban, with a negative number indicating a cost reduction. Of the 10,000 Monte-Carlo iterations 92.6%, 79.8%, and 100.0% were associated with a medical cost reduction >$0 for dabigatran, rivaroxaban, and apixaban, respectively.

Conclusions:

Usage of the NOACs, dabigatran, rivaroxaban, and apixaban may be associated with lower medical (excluding drug costs) costs relative to warfarin, with apixaban having the most substantial medical cost reduction.     

Medical costs in the US of clinical events associated with oral anticoagulant (OAC) use compared to warfarin among non-valvular atrial fibrillation patients ≥75 and <75 years of age,based on the ARISTOTLE,RE-LY,and ROCKET-AF trials

Abstract

Objectives:

Based on clinical trials the oral anticoagulants (OACs) apixaban, dabigatran, and rivaroxaban are efficacious for reducing stroke risk for non-valvular atrial fibrillation (NVAF) patients. Based on the clinical trials, this study evaluated the medical costs for clinical events among NVAF patients ≥75 and <75 years of age treated with individual OACs vs warfarin.

Methods:

Rates for primary and secondary efficacy and safety outcomes (i.e., clinical events) among NVAF patients receiving warfarin or each of the OACs were determined for NVAF populations aged ≥75 years and <75 years of age from the OAC vs warfarin trials. One-year incremental costs among patients with clinical events were obtained from published literature and inflation adjusted to 2010 costs. Medical costs, excluding medication costs, for clinical events associated with each OAC and warfarin were then estimated and compared.

Results:

Among NVAF patients aged ≥75, compared to warfarin, use of either apixaban or rivaroxaban was associated with a reduction in medical costs per patient year (apixaban?=??$825, rivaroxaban?=?$23), while dabigatran use was associated with increased medical costs of $180 per patient year. Among NVAF patients <75 years of age medical costs per patient year were estimated to be reduced ?$254, ?$367, and ?$88, for apixaban, dabigatran, and rivaroxaban, respectively, in comparison to warfarin.

Limitations:

This economic analysis was based on clinical trial data and, therefore, the direct application of the results to routine clinical practice will require further assessment.

Conclusions:

Difference in medical costs between OAC and warfarin treated NVAF patients vary by age group and individual OACs. Although reductions in medical costs for NVAF patients aged ≥75 and <75 were observed for those using either apixaban or rivaroxaban vs warfarin, the reductions were greater per patient year for both the older and younger NVAF populations using apixaban.     

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

Abstract

Objective:

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

Major bleeding risk and healthcare economic outcomes of non-valvular atrial fibrillation patients newly-initiated with oral anticoagulant therapy in the real-world setting

Aims: This study compared the risk for major bleeding (MB) and healthcare economic outcomes of patients with non-valvular atrial fibrillation (NVAF) after initiating treatment with apixaban vs rivaroxaban, dabigatran, or warfarin.

Methods: NVAF patients who initiated apixaban, rivaroxaban, dabigatran, or warfarin were identified from the IMS Pharmetrics Plus database (January 1, 2013–September 30, 2015). Propensity score matching (PSM) was used to balance differences in patient characteristics between study cohorts: patients treated with apixaban vs rivaroxaban, apixaban vs dabigatran, and apixaban vs warfarin. Risk of hospitalization and healthcare costs (all-cause and MB-related) were compared between matched cohorts during the follow-up.

Results: During the follow-up, risks for all-cause (hazard ratio [HR]?=?1.44, 95% confidence interval [CI]?=?1.2–1.7) and MB-related (HR?=?1.57, 95% CI?=?1.0–2.4) hospitalizations were significantly greater for patients treated with rivaroxaban vs apixaban. Adjusted total all-cause healthcare costs were significantly lower for patients treated with apixaban vs rivaroxaban ($3,950 vs $4,333 per patient per month [PPPM], p?=?.002) and MB-related medical costs were not statistically significantly different ($100 vs $233 PPPM, p?=?.096). Risk for all-cause hospitalization (HR?=?1.98, 95% CI?=?1.6–2.4) was significantly greater for patients treated with dabigatran vs apixaban, although total all-cause healthcare costs were not statistically different. Risks for all-cause (HR?=?2.22, 95% CI?=?1.9–2.5) and MB-related (HR?=?2.05, 95% CI?=?1.4–3.0) hospitalizations were significantly greater for patients treated with warfarin vs apixaban. Total all-cause healthcare costs ($3,919 vs $4,177 PPPM, p?=?.025) and MB-related medical costs ($96 vs $212 PPPM, p?=?.026) were significantly lower for patients treated with apixaban vs warfarin.

Limitations: This retrospective database analysis does not establish causation.

Conclusions: In the real-world setting, compared with rivaroxaban and warfarin, apixaban is associated with reduced risk of hospitalization and lower healthcare costs. Compared with dabigatran, apixaban is associated with lower risk of hospitalizations.     

Clinical and economic benefits of extended treatment with apixaban for the treatment and prevention of recurrent venous thromboembolism in Canada

Background and objective Venous thromboembolism (VTE) is associated with long-term clinical and economic burden. Clinical guidelines generally recommend at least 3 months of anticoagulation, but, in clinical practice, concerns over bleeding risk often limit extended treatment. Apixaban was studied for extended VTE treatment in the AMPLIFY-EXT trial, demonstrating superiority to placebo in VTE reduction without increasing risk of major bleeding. This study assessed the long-term clinical and economic benefits of extending treatment with apixaban when clinical equipoise exists compared to standard of care with enoxaparin/warfarin and other novel oral anti-coagulants (NOACs) for the treatment and prevention of recurrent VTE in Canada.

Methods A Markov model was developed to follow patients with VTE over their lifetimes. Efficacy and safety for apixaban and enoxaparin/warfarin were based on AMPLIFY and AMPLIFY-EXT, while relative efficacy to other NOACs was synthesized by network meta-analysis (NMA). Dosages for NOACs and enoxaparin/warfarin were based on their respective trials and were given up to 18 months and up to 6 months, followed by no treatment, respectively. Patient quality adjusted life years (QALYs) were based on published studies, and costs for resource utilization were from a Ministry of Health perspective, expressed as 2014 CAD ($).

Results Extended treatment with apixaban compared to enoxaparin/warfarin resulted in fewer recurrent VTEs, VTE-related deaths, and bleeding events, but at slightly increased cost. The incremental cost-effectiveness ratio was $4828 per QALY gained. Compared to other NOACs, apixaban had the fewest bleeding events, similar recurrent VTE events, and the lowest overall cost, which was driven by the strong bleeding profile. In scenario analyses of acute and lifetime treatments, apixaban was cost-effective against all strategies.

Conclusions Extended treatment with apixaban can offer substantial clinical benefits and is a cost-effective alternative to enoxaparin/warfarin and other NOACs.     

Stroke prevention in patients with atrial fibrillation in France: comparative cost-effectiveness of new oral anticoagulants (apixaban,dabigatran, and rivaroxaban), warfarin,and aspirin

Objectives:

To conduct an economic evaluation of the currently prescribed treatments for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) including warfarin, aspirin, and novel oral anticoagulants (NOACs) from a French payer perspective.

Methods:

A previously published Markov model was adapted in accordance to the new French guidelines of the Commission for Economic Evaluation and Public Health (CEESP), to adopt the recommended efficiency frontier approach. A cohort of patients with NVAF eligible for stroke preventive treatment was simulated over lifetime. Clinical events modeled included strokes, systemic embolism, intracranial hemorrhage, other major bleeds, clinically relevant non-major bleeds, and myocardial infarction. Efficacy and bleeding data for warfarin, apixaban, and aspirin were obtained from ARISTOTLE and AVERROES trials, whilst efficacy data for other NOACs were from published indirect comparisons. Acute medical costs were obtained from a dedicated analysis of the French national hospitalization database (PMSI). Long-term medical costs and utility data were derived from the literature. Univariate and probabilistic sensitivity analyses were performed to assess the robustness of the model projections.

Results:

Warfarin and apixaban were the two optimal treatment choices, as the other five treatment strategies including aspirin, dabigatran 110?mg, dabigatran in sequential dosages, dabigatran 150?mg, and rivaroxaban were strictly dominated on the efficiency frontier. Further, apixaban was a cost-effective alternative vs warfarin with an incremental cost of €2314 and an incremental quality-adjusted life year (QALY) of 0.189, corresponding to an incremental cost-effectiveness ratio (ICER) of €12,227/QALY.

Conclusions:

Apixaban may be the most economically efficient alternative to warfarin in NVAF patients eligible for stroke prevention in France. All other strategies were dominated, yielding apixaban as a less costly yet more effective treatment alternative. As formally requested by the CEESP, these results need to be verified in a French clinical setting using stroke reduction and bleeding safety observed in real-life patient cohorts using these anticoagulants.     

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

Abstract

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 rivaroxaban versus apixaban for the initial treatment of venous thromboembolism and extended prevention of recurrences in the UK

Abstract

Aim: To evaluate the relative cost-effectiveness of using rivaroxaban vs apixaban for the initial treatment plus extended prevention of venous thromboembolism (VTE) in the UK. Extended prevention was assessed using a 10-mg rivaroxaban dose, as the 20-mg dose has already been evaluated.

Methods: A Markov model compared the health outcomes and costs of treating VTE patient cohorts with either rivaroxaban (15?mg twice daily for 3 weeks, followed by 20?mg once daily for 6 months, then extended prevention with 10?mg once daily) or apixaban (10?mg twice daily for 1 week, followed by 5?mg twice daily for 6 months, then extended prevention with 2.5?mg twice daily) over a lifetime horizon. The model included an initial acute treatment and prevention phase (0–6?months) and an extended prevention phase (6–18 months). Efficacy and safety data were derived from two network meta-analyses. Reference treatment comparators were derived from the EINSTEIN-Pooled study and EINSTEIN-CHOICE trial. Healthcare costs and utility data were derived from published literature.

Results: The rivaroxaban regimen was associated with increased quality-adjusted life years (QALYs) and slightly lower total costs compared with apixaban over a lifetime horizon. Deterministic and probabilistic sensitivity analyses demonstrated that rivaroxaban remained a cost-effective alternative to apixaban over a wide range of parameters. Incremental cost-effectiveness ratio estimates were below the £20,000 per QALY threshold in 74.1% of 2,000 model simulations. Scenario analyses further supported that rivaroxaban is a cost-effective alternative to apixaban.

Limitations: Clinical and safety inputs were derived from network meta-analysis, which are subject to inherent limitations whereby small differences between study designs may severely impact efficacy and safety outcomes. Furthermore, these inputs were based on data from clinical trials, which may not reflect real-world data.

Conclusions: Rivaroxaban was associated with a slightly lower total cost and increased QALYs compared with apixaban for VTE management in the UK over a lifetime horizon.     

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.     

Cost and outcomes associated with rivaroxaban vs enoxaparin for the prevention of postsurgical venous thromboembolism from a US payer’s perspective

Abstract

Objective:

The objective of this analysis was the evaluation of the outcomes and costs associated with rivaroxaban and enoxaparin for the prevention of postsurgical venous thromboembolism (VTE) in patients undergoing total hip replacement (THR) and total knee replacement (TKR) from the US payer perspective.

Methods:

VTE event rates have been reported in three Phase III clinical trials that compared rivaroxaban and enoxaparin for VTE prevention after orthopedic surgery during the prophylaxis (≤35 days for THR patients and 10–14 days for TKR patients) and post-prophylaxis periods (≤90 days following surgery). These data were used in this decision-analytic model to estimate and compare health outcomes and costs associated with rivaroxaban and enoxaparin. The base-case analysis considered the number and costs of symptomatic VTE events during the prophylaxis period only. A 90-day horizon was considered in the sensitivity analysis.

Results:

Following THR, when extended durations of prophylaxis (35 days) were compared, rivaroxaban was associated with lower costs than enoxaparin, with total saving costs of $695/patient. When an extended duration of rivaroxaban prophylaxis (35 days) was compared with a short duration (10–14 days) of enoxaparin prophylaxis, rivaroxaban was estimated to prevent 9.9 additional symptomatic VTE events per 1000 patients, while saving $244/patient (rate/1000 patients). In the TKR population, short duration of rivaroxaban prophylaxis was estimated to prevent 13.1 additional symptomatic VTE events per 1000 patients. It was also less costly than short duration enoxaparin prophylaxis, with a saving of $411/patient (rate/1000 patients).

Limitations:

Only statistically significant differences were captured in the base-case economic analysis, and, therefore, differences in pulmonary embolism (PE) and bleeding events were not captured.

Conclusions:

In this model, rivaroxaban reduced total treatment payer costs vs enoxaparin for the prevention of VTE in THR or TKR patients.     

Healthcare resource utilization and costs associated with venous thromboembolism in cancer patients treated with anticoagulants

Abstract

Objective: The standard of care for cancer-related venous thromboembolism (VTE) has been low molecular weight heparin (LMWH), but oral anticoagulants are also widely prescribed. This study compared VTE-related healthcare resource utilization and costs of cancer patients treated with anticoagulants.

Methods: Claims data from Humana Database (January 1, 2013–May 31, 2015) were analyzed. Based on the first anticoagulant received, patients were classified into LMWH, warfarin, or rivaroxaban cohorts. Characteristics were evaluated during the 6 months pre-index date (i.e. the first VTE); VTE-related resource utilization and costs were evaluated during follow-up. Cohorts were compared using rate ratios, and p-values and 95% confidence intervals were calculated. Healthcare costs were evaluated per-patient-per-year (PPPY) and compared using mean cost differences.

Results: A total of 2,428 patients (LMWH: n?=?660; warfarin: n?=?1,061; rivaroxaban: n?=?707) were included. Compared to patients treated with LMWH, patients treated with rivaroxaban had significantly fewer VTE-related hospitalizations, hospitalization days, and emergency room and outpatient visits, resulting in an increase of $12,000 VTE-related healthcare costs PPPY with LMWH vs rivaroxaban. Patients treated with rivaroxaban had significantly lower VTE-related resource utilization compared to patients treated with warfarin; however, VTE-related costs were similar between cohorts. The higher drug costs ($1,519) were offset by significantly lower outpatient (?$1,039) and hospitalization costs (?$522) in rivaroxaban relative to the warfarin cohort.

Conclusions: Healthcare resource use and costs associated with VTE treatment in cancer patients are highest with LMWH relative to warfarin and rivaroxaban.     

Real-world comparison of all-cause hospitalizations,hospitalizations due to stroke and major bleeding,and costs for non-valvular atrial fibrillation patients prescribed oral anticoagulants in a US health plan

Aims: To compare the risk of all-cause hospitalization and hospitalizations due to stroke/systemic embolism (SE) and major bleeding, as well as associated healthcare costs for non-valvular atrial fibrillation (NVAF) patients initiating apixaban, dabigatran, rivaroxaban, or warfarin.

Materials and methods: NVAF patients initiating apixaban, dabigatran, rivaroxaban, or warfarin were selected from the OptumInsight Research Database from January 1, 2013–September 30, 2015. Propensity score matching (PSM) was performed between apixaban and each oral anticoagulant. Cox models were used to estimate the risk of stroke/SE and major bleeding. Generalized linear and 2-part models were used to compare healthcare costs.

Results: Of the 47,634 eligible patients, 8,328 warfarin-apixaban pairs, 3,557 dabigatran-apixaban pairs, and 8,440 rivaroxaban-apixaban pairs were matched. Compared to apixaban, warfarin patients were associated with a significantly higher risk of all-cause (hazard ratio [HR]?=?1.30; 95% confidence interval [CI]?=?1.21–1.40) as well as stroke/SE-related (HR?=?1.60; 95% CI?=?1.23–2.07) and major bleeding-related (HR?=?1.95; 95% CI?=?1.60–2.39) hospitalization; rivaroxaban patients were associated with a higher risk of all-cause (HR?=?1.15; 95% CI?=?1.07–1.24) and major bleeding-related hospitalization (HR?=?1.71; 95% CI?=?1.39–2.10); and dabigatran patients were associated with a higher risk of major bleeding hospitalization (HR?=?1.46, 95% CI?=?1.02–2.10). Warfarin patients had significantly higher major bleeding-related and total all-cause healthcare costs compared to apixaban patients. Rivaroxaban patients had significantly higher major bleeding-related costs compared to apixaban patients. No significant results were found for the remaining comparisons.

Limitations: No causal relationships can be concluded, and unobserved confounders may exist in this retrospective database analysis.

Conclusions: This study demonstrated a significantly higher risk of hospitalization (all-cause, stroke/SE, and major bleeding) associated with warfarin, a significantly higher risk of major bleeding hospitalization associated with dabigatran or rivaroxaban, and a significantly higher risk of all-cause hospitalization associated with rivaroxaban compared to apixaban. Lower major bleeding-related costs were observed for apixaban patients compared to warfarin and rivaroxaban patients.     

Cost-effectiveness of rivaroxaban compared with enoxaparin plus a vitamin K antagonist for the treatment of venous thromboembolism

Background:

Venous thromboembolism (VTE), comprised of deep vein thrombosis (DVT) and pulmonary embolism (PE), is commonly treated with a low-molecular-weight heparin such as enoxaparin plus a vitamin K antagonist (VKA) to prevent recurrence. Administration of enoxaparin?+?VKA is hampered by complexities of laboratory monitoring and frequent dose adjustments. Rivaroxaban, an orally administered anticoagulant, has been compared with enoxaparin?+?VKA in the EINSTEIN trials. The objective was to evaluate the cost-effectiveness of rivaroxaban compared with enoxaparin?+?VKA as anticoagulation treatment for acute, symptomatic, objectively-confirmed DVT or PE.

Methods:

A Markov model was built to evaluate the costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios associated with rivaroxaban compared to enoxaparin?+?VKA in adult patients treated for acute DVT or PE. All patients entered the model in the ‘on-treatment’ state upon commencement of oral rivaroxaban or enoxaparin?+?VKA for 3, 6, or 12 months. Transition probabilities were obtained from the EINSTEIN trials during treatment and published literature after treatment. A 3-month cycle length, US payer perspective ($2012), 5-year time horizon and a 3% annual discount rate were used.

Results:

Treatment with rivaroxaban cost $2,448 per-patient less and was associated with 0.0058 more QALYs compared with enoxaparin?+?VKA, making it a dominant economic strategy. Upon one-way sensitivity analysis, the model’s results were sensitive to the reduction in index VTE hospitalization length-of-stay associated with rivaroxaban compared with enoxaparin?+?VKA. At a willingness-to-pay threshold of $50,000/QALY, probabilistic sensitivity analysis showed rivaroxaban to be cost-effective compared with enoxaparin?+?VKA approximately 76% of the time.

Limitations:

The model did not account for the benefits associated with an oral and minimally invasive administration of rivaroxaban. ‘Real-world’ applicability is limited because data from the EINSTEIN trials were used in the model. Also, resource utilization and costs were based on the US healthcare system.

Conclusion:

Rivaroxaban is a cost-effective option for anticoagulation treatment of acute VTE patients.     

Estimated medical cost reductions associated with apixaban in real-world patients with non-valvular atrial fibrillation

Abstract

Objective:

The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial demonstrated that apixaban was effective in reducing the risk of stroke and major bleeding in non-valvular atrial fibrillation (NVAF) patients. Medical cost avoidance studies for oral anticoagulants have used warfarin event rates from clinical trials, which may not reflect the real-world (RW) setting. This study aimed to estimate the difference in medical costs associated with apixaban instead of warfarin in RW NVAF patients.

Methods:

This study selected patients with NVAF diagnosis during 2007–2010 from a Medco population of US commercial and Medicare health plans. Stroke and major bleeding excluding intracranial hemorrhage (MBEIH) were identified using diagnosis codes. Pharmacy claims were used to define warfarin exposure periods. Rates of stroke and MBEIH were calculated during warfarin exposure. To estimate the absolute risk reduction (ARR) between warfarin and apixaban in RW, the relative risk reductions (RRR) from ARISTOTLE were multiplied by the event rates observed in RW during warfarin exposure. Medical cost reductions associated with apixaban were calculated by applying the ARR to the 1-year incremental cost for each event. Stroke and MBEIH costs were obtained from the literature and adjusted to 2011 levels.

Results:

During a patient year, the use of apixaban instead of warfarin resulted in medical cost reductions of $493 for stroke and $752 for MBEIH and $1245 for the combined outcome of both events. The medical costs avoided were greater as baseline stroke risk increased.

Conclusion:

If RRRs demonstrated in ARISTOTLE persist in RW, the use of apixaban will be associated with lower medical costs vs warfarin. Main limitations of this study were: identification of clinical events using administrative codes rather than confirmatory clinical data, inability to evaluate the level of international normalized ratio (INR) control, and not including INR monitoring and drug costs.     

Length of stay and economic consequences with rivaroxaban vs enoxaparin/vitamin K antagonist in patients with DVT and PE: findings from the North American EINSTEIN clinical trial program

Objective:

Venous thromboembolism (VTE) (deep vein thrombosis [DVT] and pulmonary embolism [(PE]) represents a substantial economic burden to the healthcare system. Using data from the randomized EINSTEIN DVT and PE trials, this North American sub-group analysis investigated the potential of rivaroxaban to reduce the length of initial hospitalization in patients with acute symptomatic DVT or PE.

Methods:

A post-hoc analysis of hospitalization and length-of-stay (LOS) data was conducted in the North American sub-set of patients from the randomized, open-label EINSTEIN trial program. Patients received either rivaroxaban (15?mg twice daily for 3 weeks followed by 20?mg once daily; n?=?405) or dose-adjusted subcutaneous enoxaparin overlapping with (guideline-recommended ‘bridging’ therapy) and followed by a vitamin K antagonist (VKA) (international normalized ratio?=?2.0–3.0; n?=?401). The open-label study design allowed for the comparison of LOS between treatment arms under conditions reflecting normal clinical practice. LOS was evaluated using investigator records of dates of admission and discharge. Analyses were carried out in the intention-to-treat population using parametric tests. Costs were applied to the LOS based on weighted mean cost per day for DVT and PE diagnoses obtained from the Healthcare Cost and Utilization Project dataset.

Results:

Of 382 patients hospitalized, 321 (84%), had acute symptomatic PE; few DVT patients required hospitalization. Similar rates of VTE patients were hospitalized in the rivaroxaban and enoxaparin/VKA treatment groups, 189/405 (47%) and 193/401 (48%), respectively. In hospitalized VTE patients, rivaroxaban treatment produced a 1.6-day mean reduction in LOS (median?=?1 day) compared with enoxaparin/VKA (mean?=?4.5 vs 6.1; median?=?3 vs 4), translating to total costs that were $3419 lower in rivaroxaban-treated patients.

Conclusion:

In hospitalized North American patients with VTE, treatment with rivaroxaban produced a statistically significant reduction in LOS. When treating DVT and PE patients, clinicians should consider newer anti-coagulants with less complex treatment regimens.     

Cost comparison of continued anticoagulation with rivaroxaban versus placebo based on the 1-year EINSTEIN-Extension trial efficacy and safety results

Aims: The EINSTEIN-Extension trial (EINSTEIN-EXT) found that continued treatment with rivaroxaban for an additional 6 or 12 months (vs placebo) after 6–12 months of initial anticoagulation significantly reduced the risk of recurrent venous thromboembolism (VTE) with a small non-significant increased risk of major bleeding (none fatal or in critical site). This study aimed to compare total healthcare cost between rivaroxaban and placebo, based on the EINSTEIN-EXT event rates.

Methods: Total healthcare cost was calculated as the sum of treatment and clinical event costs from a US managed care perspective. Treatment duration and event rates were obtained from the EINSTEIN-EXT study. Adjustment on treatment duration was made by assuming a 10% non-adherence rate. Drug costs were based on wholesale acquisition costs. Cost estimates for clinical events (i.e. recurrent deep vein thrombosis [DVT], recurrent pulmonary embolism, major bleeding, clinically relevant non-major bleeding) were determined from the literature. Results were examined over a ±20% range of each cost component and over 95% confidence intervals (CIs) of event rate differences in deterministic (one-way) and probabilistic sensitivity analyses (PSA).

Results: Total healthcare cost was $1,454 lower for rivaroxaban-treated (vs placebo-treated) patients in the base-case, with a lower clinical event cost fully offsetting drug cost. The cost savings of recurrent DVT alone (–$3,102) was greater than drug cost ($2,723). Total healthcare cost remained lower for rivaroxaban in the majority (73%) of PSA (cost difference [95% CI]?=?–$1,454 [–$2,396, $1,231]).

Limitations: This study was conducted over the 1-year observation period of the EINSTEIN-EXT trial, which limited “real-world” applicability and examination of long-term economic impact. Assumptions on drug and clinical event costs were US-based and, thus, not applicable to other healthcare systems.

Conclusions: Total healthcare costs were estimated to be lower for patients continuing rivaroxaban therapy compared to those receiving placebo in VTE patients who had completed 6–12 months of VTE treatment.     

Number needed to treat based on real-world evidence for non-vitamin K antagonist oral anticoagulants versus vitamin K antagonist oral anticoagulants in stroke prevention in patients with non-valvular atrial fibrillation

Aims: Non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (VKAs) are used to prevent stroke in patients with atrial fibrillation (AF). This paper aimed to evaluate the clinical efficacy and safety of NOACs when compared to VKAs by calculating the number needed to treat (NNT) at 2 years using incidence rates and hazard ratios (HRs) derived from a meta-analysis of studies conducted in real-world settings.

Materials and methods: HRs were sourced from a published systematic literature review and a meta-analysis of real-world evidence on the use of NOACs vs VKAs. Rivaroxaban, dabigatran, and apixaban vs VKAs were investigated. The efficacy outcomes included: a composite of ischaemic stroke and systemic embolism (IS/SE), ischaemic stroke (IS), and all-cause mortality. The safety analysis assessed major bleeding and intracranial haemorrhage (ICH).

Results: Superiority of NOACs vs VKAs was observed in 10/15 comparisons. Treating patients with rivaroxaban and dabigatran was associated with a reduced risk of IS and all-cause mortality compared to VKAs, with one death prevented every 22 and 32 patients, respectively, and one IS prevented every 206 and 166 patients, respectively. Rivaroxaban was significantly associated with a reduced risk of IS/SE compared to VKA (NNT: 107). No significant differences were observed between apixaban and VKAs. Dabigatran and apixaban were associated with a reduced risk of major bleeding compared to VKA (NNT: 59 and 38, respectively). No significant difference was observed between rivaroxaban and VKAs regarding major bleeding. Rivaroxaban, dabigatran, and apixaban were significantly associated with a reduced risk of ICH (NNT: 205, 115, and 108, respectively).

Limitations: Heterogeneity in definitions of major bleeding across studies.

Conclusions: The NNT calculation, when approached and interpreted properly, is a practical measure of the effectiveness of a treatment. The calculation based on HRs showed that NOACs are safe and effective alternatives to VKAs in real life.     

Costs of hospital visits among patients with deep vein thrombosis treated with rivaroxaban and LMWH/warfarin

Background:

For many years, the standard of care for patients diagnosed with deep vein thrombosis (DVT) has been low-molecular-weight heparin (LMWH) bridging to an oral Vitamin-K antagonist (VKA). The availability of new non-VKA oral anticoagulants (NOAC) agents as monotherapy may reduce the likelihood of hospitalization for DVT patients.

Objective:

To compare hospital visit costs of DVT patients treated with rivaroxaban and LMWH/warfarin.

Methods:

A retrospective claim analysis was conducted using the MarketScan Hospital Drug Database for care provided between January 2011 and December 2013. Adult patients using rivaroxaban or LMWH/warfarin with a primary diagnosis of DVT during the first day of a hospital visit were identified (i.e., index hospital visit). Based on propensity-score methods, historical LMWH/warfarin patients (i.e., patients who received LMWH/warfarin before the approval of rivaroxaban) were matched 4:1 to rivaroxaban patients. The hospital-visit cost difference between these groups was evaluated for the index hospital visit, as well as for total hospital-visit costs (i.e., including index and subsequent hospital visit costs).

Results:

All rivaroxaban users (n?=?134) in the database were well-matched with four LMWH/warfarin users (n?=?536). The mean hospital-visit costs were $5257 for the rivaroxaban cohort and $6764 in the matched-cohort of patients using LMWH/warfarin. The $1508 cost difference was statistically significant between cohorts (95% CI?=?[?$2296; ?$580]; p-value?=?0.002). Total hospital-visit costs were lower for rivaroxaban compared to LMWH/warfarin users within 1, 2, 3, and 6 months after index visit (significantly lower within 1 and 3 months, p-values <0.05)

Limitations:

Limitations were inherent to administrative-claims data, completeness of baseline characteristics, adjustments restricted to observational factors, and lastly the sample size of the rivaroxaban cohort.

Conclusion:

The availability of rivaroxaban significantly reduced the costs of hospital visits in patients with DVT treated with rivaroxaban compared to LMWH/warfarin.     

Cost-effectiveness analysis of rivaroxaban for treatment and secondary prevention of venous thromboembolism in the Netherlands

Background: Until recently, standard treatment of venous thromboembolism (VTE) concerned a combination of short-term low-molecular-weight heparin (LMWH) and long-term vitamin-K antagonist (VKA). Risk of bleeding and the requirement for regular anticoagulation monitoring are, however, limiting their use. Rivaroxaban is a novel oral anticoagulant associated with a significantly lower risk of major bleeds (hazard ratio?=?0.54, 95% confidence interval?=?0.37–0.79) compared to LMWH/VKA therapy, and does not require regular anticoagulation monitoring.

Aims: To evaluate the health economic consequences of treating acute VTE patients with rivaroxaban compared to treatment with LMWH/VKA, viewed from the Dutch societal perspective.

Methods: A life-time Markov model was populated with the findings of the EINSTEIN phase III clinical trial to analyze cost-effectiveness of rivaroxaban therapy in treatment and prevention of VTE from a Dutch societal perspective. Primary model outcomes were total and incremental quality-adjusted life years (QALYs), as well as life expectancy and costs.

Results: Over a patient’s lifetime, rivaroxaban was shown to be dominant, with health gains of 0.047 QALYs and cost savings of €304 compared to LMWH/VKA therapy. Dominance was robustly present in all sensitivity analyses. Major drivers of the differences between the two treatment arms were related to anticoagulation monitoring (medical costs, travel costs, and loss of productivity) and the occurrence of major bleeds.

Conclusion: Rivaroxaban treatment of patients with venous thromboembolism results in health gains and cost savings compared to LMWH/VKA therapy. This conclusion holds for the Dutch setting, both for the societal perspective, as well as the healthcare perspective.