Raspin Christopher, Faught Edward, Armand Jeanne, Barion Francesca, Pollit Vicki, Murphy Joanna, Danielson Vanessa
Symmetron Limited, London, UK.
Department of Neurology, Emory University, Atlanta, GA, USA.
J Med Econ. 2023 Jan-Dec;26(1):189-199. doi: 10.1080/13696998.2023.2171230.
People with recurrent epileptic seizures are typically treated with anti-seizure medications (ASMs). Around a third of epilepsy patients fail to achieve an adequate response to ASMs and may be eligible to receive vagus nerve stimulation (VNS) therapy for their drug-resistant epilepsy (DRE) if they are unsuited to surgery. VNS received approval from the United States (US) Food and Drug Administration agency. However, there has to date been no comprehensive cost effectiveness evaluation of VNS within the US setting. This study was designed, using a US Medicare perspective, to estimate costs and quality-adjusted life years (QALYs) associated with VNS as an adjunct to ongoing ASM therapy, compared to ASMs alone.
We developed a cohort state transition model in Microsoft Excel, with four health states defined by different percentage reductions in seizure frequency, with a 3-month cycle and transition probabilities derived from published clinical trials and registry data. Sensitivity analyses were conducted to understand the impact of parameter uncertainty. Costs included the VNS device, placement, programming, battery changes, and removal; ASM therapy; adverse events associated with VNS (dyspnea, hoarseness, and cough); and costs associated with seizure burden (i.e. hospitalizations, emergency department visits, neurologist visits).
Under base case assumptions, treatment with VNS was associated with a 0.385 QALY gain and a $109,678 saving per patient, when compared with ASM therapy alone. The incremental net monetary benefit (iNMB) was $128,903 at a threshold of $50,000 per QALY, with the positive iNMB indicating that VNS is a highly cost effective treatment. This result is explained by the modeled reduction in relative seizure frequency and associated reduction in healthcare resource use that the VNS group experienced. Sensitivity analyses supported this conclusion.
VNS was evaluated as a cost effective addition to the current standard of care in the treatment of DRE in the US Medicare context.
复发性癫痫发作的患者通常采用抗癫痫药物（ASMs）进行治疗。约三分之一的癫痫患者对ASMs未能产生充分反应，如果不适合手术，他们可能有资格接受迷走神经刺激（VNS）疗法来治疗其耐药性癫痫（DRE）。VNS已获得美国食品药品监督管理局的批准。然而，迄今为止，在美国环境下尚未对VNS进行全面的成本效益评估。本研究从美国医疗保险的角度进行设计，旨在估计与VNS作为正在进行的ASM治疗辅助手段相比，单独使用ASMs时的成本和质量调整生命年（QALYs）。
我们在Microsoft Excel中开发了一个队列状态转换模型，通过癫痫发作频率不同百分比的降低定义了四种健康状态，以3个月为一个周期，转换概率来自已发表的临床试验和登记数据。进行敏感性分析以了解参数不确定性的影响。成本包括VNS设备、植入、编程、电池更换和移除；ASM治疗；与VNS相关的不良事件（呼吸困难、声音嘶哑和咳嗽）；以及与癫痫发作负担相关的成本（即住院、急诊就诊、神经科就诊）。
在基本情况假设下，与单独使用ASM治疗相比，VNS治疗使每位患者的QALY增加0.385，节省109,678美元。在每QALY 50,000美元的阈值下，增量净货币效益（iNMB）为128,903美元，iNMB为正表明VNS是一种极具成本效益的治疗方法。这一结果可通过VNS组癫痫发作相对频率建模降低以及相关医疗资源使用减少来解释。敏感性分析支持这一结论。
在美国医疗保险背景下，VNS被评估为治疗DRE的当前护理标准中具有成本效益的补充治疗方法。
