Cost-Utility Analysis of Mechanical Thrombectomy Using Stent Retrievers in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Recently, 5 randomized controlled trials demonstrated the benefit of endovascular therapy compared with intravenous tissue-type plasminogen activator in acute stroke. Economic evidence evaluating stent retrievers is limited. We compared the cost-effectiveness of intravenous tissue-type plasminogen activator alone versus mechanical thrombectomy and intravenous tissue-type plasminogen activator as a bridging therapy in eligible patients in the UK National Health Service. METHODS: A model-based cost-utility analysis was performed using a lifetime horizon. A Markov model was constructed and populated with probabilities, outcomes, and cost data from published sources, including 1-way and probabilistic sensitivity analysis. RESULTS: Mechanical thrombectomy was more expensive than intravenous tissue-type plasminogen activator, but it improved quality-adjusted life expectancy. The incremental cost per (quality-adjusted life year) gained of mechanical thrombectomy over a 20 year period was $11 651 (£7061). The probabilistic sensitivity analysis demonstrated that thrombectomy had a 100% probability of being cost-effective at the minimum willingness to pay for a quality-adjusted life year commonly used in United Kingdom. CONCLUSIONS: Although the upfront costs of thrombectomy are high, the potential quality-adjusted life year gains mean this intervention is cost-effective. This is an important factor for consideration in deciding whether to commission this intervention.

Indirect comparison and cost-utility of dabigatran etexilate and rivaroxaban in the treatment and extended anticoagulation of venous thromboembolism in a UK setting.

BACKGROUND: Acute venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is traditionally managed with a short course of parenteral anticoagulation followed by 3-6 months of a vitamin-K antagonist. Non-vitamin K oral anticoagulants (NOACs) do not require routine monitoring and dose adjustment, thus potentially provide an alternative treatment option. METHODS AND RESULTS: Because of the lack of head-to-head clinical studies, an indirect comparison was conducted of dabigatran etexilate and rivaroxaban based on the respective phase III clinical trial. The derived relative safety and efficacy estimates were used to evaluate the cost-utility of dabigatran compared with rivaroxaban in the treatment and secondary prevention of VTE. The results of the indirect comparison showed no significant difference between dabigatran and rivaroxaban in avoiding recurrent VTE following index PE, index DVT, or DVT/PE combined, in treatment and extended anticoagulation. Dabigatran has significantly less major or clinically relevant bleeds (MCRBE) compared to rivaroxaban in treatment after index DVT and treatment after DVT or PE combined, but was not significantly different from rivaroxaban after index PE or in extended anticoagulation. In cost-utility deterministic analyses, dabigatran was projected dominant in all analyzed settings, given its marginally lower total cost and marginally higher QALYs gained compared to rivaroxaban. Probabilistic analyses results showed a high likelihood of dabigatran being considered good value for money in the UK, in treatment and in secondary prevention of VTE. CONCLUSION: The cost-effectiveness evaluations showed that dabigatran can be considered the dominant treatment strategy compared to rivaroxaban in the patients' sub-groups considered, given the projected marginally higher clinical benefits and lower treatment costs.

The cost-utility of dabigatran etexilate compared with warfarin in treatment and extended anticoagulation of acute VTE in the UK.

The relative efficacy and safety of dabigatran etexilate and warfarin have been evaluated in two head-to-head, phase III, treatment of acute venous thromboembolism (VTE) trials, and one extended prophylaxis trial, in patients with high risk of recurrent VTE. Dabigatran etexilate demonstrated similar efficacy to warfarin, and was associated with a reduced risk of major or clinically relevant bleeds. Based on results of these trials, and real-life disease prognosis following discontinuation of anticoagulation treatment, we evaluated the cost-utility of dabigatran etexilate compared with warfarin in six months anticoagulation, and in extended, up to 24 months anticoagulation, in patients with acute VTE, acute deep-vein thrombosis (DVT) or acute, symptomatic, pulmonary embolism (PE). Costs were analysed from the perspective of the National Health Services (NHS) and Public Social Services (PSS) in England and Wales. Outcomes were quantified in quality-adjusted life years (QALY). The estimated incremental, lifetime cost/QALY gain following acute, symptomatic VTE (DVT or PE) was £1,252/QALY when dabigatran etexilate or warfarin were administered for up to six months treatment. In treatment of acute, symptomatic PE and in DVT respective ratios were £1,767/QALY and £1,075/QALY. In extended, up to 24 months anticoagulation, dabigatran etexilate projected costs/QALY of £8,242/QALY, when compared with warfarin. Results obtained herein were robust across a number of sensitivity analyses and suggest dabigatran etexilate to be a cost-effective alternative to current standard of care when evaluated in six months treatment and in extended anticoagulation following acute VTE (DVT and/or PE).

Determinants of oral anticoagulation control in new warfarin patients: analysis using data from Clinical Practice Research Datalink.

BACKGROUND: The safety and effectiveness of warfarin therapy depends critically on the quality of anticoagulation control, often assessed using the percentage time in therapeutic International Normalised Ratio (INR) range (TTR). We aimed to identify patient characteristics related to anticoagulation control with warfarin, measured by TTR. METHOD: We carried out a population-based study using the Clinical Practice Research Datalink, including two cohorts of patients starting warfarin after a first diagnosis of atrial fibrillation (AF) or venous thromboembolism (VTE) between 2000 and 2013. We used multivariate mixed regression and logistic regression models to predict the fully-adjusted effect of each predictor variable upon TTR. RESULTS: The study population comprised 29,717 incident AF and 19,113 incident VTE patients who initiated warfarin. In real world clinical practice a minority of patients achieve good anticoagulation control with warfarin (44% AF and 36% VTE patients had TTR≥70%). Poor anticoagulation control driven by subtherapeutic INRs was observed in younger patients (<45years) and in AF patients with increased number of hospitalisations. Poor anticoagulation control driven by sub and/or supratherapeutic INRs was seen in AF and VTE patients current smokers, in patients using medications for pain and in VTE patients with active cancer. CONCLUSION: In a real world clinical practice there is a high amount of unpredictable inter-individual TTR variability and in some patients good anticoagulation control is more challenging than in others. These findings may help to identify patients who will require closer monitoring or innovative strategies to optimise the outcomes of oral anticoagulant therapy.

Comparison of the cost-effectiveness of new oral anticoagulants for the prevention of stroke and systemic embolism in atrial fibrillation in a UK setting.

PURPOSE: Three new oral anticoagulants (NOACs) have recently become available in the United Kingdom as an alternative to warfarin in the prevention of stroke and systemic embolism in atrial fibrillation. This study examines the relative cost-effectiveness of dabigatran (BID dosing of 150 mg or 110 mg based on patient age), rivaroxaban, and apixaban from a UK payer perspective. METHODS: A previously published model that follows up patients through treatment of atrial fibrillation during a lifetime was adapted to allow comparison of the 3 NOACs and warfarin. Acute thromboembolic and bleeding events, as well as long-term consequences of stroke, intracranial hemorrhage, and acute myocardial infarction, were tracked. Relative efficacy was calculated from a formal indirect treatment comparison using data from the 3 key trials (Randomized Evaluation of Long-Term Anticoagulation Therapy, Rivaroxaban Once-daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation, and Apixaban for the Prevention of Stroke in Subjects With Atrial Fibrillation) of the NOACs. Data from the rivaroxaban trial were adjusted for the difference in international normalized ratio control among warfarin patients versus the other 2 trials. Model outputs included total costs, event rates, and quality-adjusted life-years. FINDINGS: Among the patients taking NOACs, those taking dabigatran had the highest total QALYs (7.68 QALYs), followed by apixaban (7.63 QALYs) and rivaroxaban (7.47 QALYs). Patients taking dabigatran had the lowest total lifetime costs (£23,342), followed by apixaban (£24,014) and rivaroxaban (£25,220). The differences between dabigatran and apixaban were modest but consistent in sensitivity analyses, with the directionality only changing at the limits of the CIs for the relative risks of ischemic stroke or intracranial hemorrhage or when assuming that both treatment discontinuation and post-event disability rates differ by drug. IMPLICATIONS: Dabigatran was found to be economically dominant over rivaroxaban and apixaban in the UK setting. These economic findings are based on relative clinical efficacy from an indirect treatment comparison and would benefit from any data of direct comparisons of the NOACs in the future.