Department of Internal Medicine, Cardinal Massaia Hospital, Asti, Italy.
Eur J Health Econ. 2013 Dec;14(6):853-61. doi: 10.1007/s10198-012-0430-7. Epub 2012 Sep 14.
Top-down (TD) strategy with frontline infliximab proved to be more effective than the traditional step-up (SU) approach in newly diagnosed luminal moderate-to-severe CD patients. However, the considerable cost of infliximab calls its universal use as frontline treatment into question. The aim of this study is to evaluate the cost-effectiveness of the TD approach using a Markov decision model.
Four states were modelled, namely step 1, step 2, step 3 and death. The first three steps were in TD infliximab induction plus azathioprine, infliximab rechallenge plus azathioprine and steroids plus azathioprine, and in SU steroid induction, azathioprine plus steroid rechallenge and infliximab plus azathioprine. Each health state lasted 1 month. The time horizon of the model was 5 years. Transition probabilities and quality of life were estimated from a randomised trial. First- and second-order sensitivity analyses were done to test the robustness of the results.
At baseline analysis, TD improved quality-adjusted life expectancy from 3.76 to 3.90 quality-adjusted life years (QALYs), that is, 0.14 QALYs, while allowing a saving of euro 773, proving dominant when compared to SU. TD was cost-saving in 66% of the Monte Carlo simulations and cost <euro 20,000/QALY in 84%. At sensitivity analysis the most significant variables were infliximab cost and time horizon: doubling infliximab cost (euro 1,000 per 100 mg vial) resulted in an incremental cost-utility ratio of euro 12,114/QALY.
TD is a cost-effective treatment in newly diagnosed CD patients with luminal moderate-to-severe disease, and sensitivity analysis showed the result to be robust.
在新诊断的腔道中重度 CD 患者中，与传统的逐步升级（step-up，SU）方法相比，自上而下（top-down，TD）策略联合一线英夫利昔单抗治疗更为有效。然而，英夫利昔单抗的高昂费用使其作为一线治疗的广泛应用受到质疑。本研究旨在通过马尔可夫决策模型评估 TD 方法的成本效益。
模型模拟了 4 种状态，分别为第 1 步、第 2 步、第 3 步和死亡。前 3 步分别为 TD 英夫利昔单抗诱导+硫唑嘌呤、英夫利昔单抗再挑战+硫唑嘌呤和类固醇+硫唑嘌呤，以及 SU 皮质类固醇诱导、硫唑嘌呤+皮质类固醇再挑战和英夫利昔单抗+硫唑嘌呤。每个健康状态持续 1 个月。模型的时间范围为 5 年。通过随机试验估计转移概率和生活质量。进行了一阶和二阶敏感性分析，以检验结果的稳健性。
在基线分析中，TD 使质量调整生命期望从 3.76 提高到 3.90 个质量调整生命年（quality-adjusted life years，QALYs），即 0.14 QALYs，同时节省了 773 欧元，与 SU 相比具有优势。在 66%的蒙特卡罗模拟中，TD 是成本节约的，在 84%的模拟中，TD 的成本低于 20,000 欧元/QALY。在敏感性分析中，最显著的变量是英夫利昔单抗的成本和时间范围：英夫利昔单抗成本翻一番（每 100mg 小瓶 1000 欧元）会导致增量成本-效用比为 12,114 欧元/QALY。
在新诊断的腔道中重度 CD 患者中，TD 是一种具有成本效益的治疗方法，敏感性分析显示结果稳健。
