Sanders Gillian D, Hlatky Mark A, Owens Douglas K
Duke Clinical Research Institute, Duke University, Durham, NC 27715, USA.
N Engl J Med. 2005 Oct 6;353(14):1471-80. doi: 10.1056/NEJMsa051989.
Eight randomized trials have evaluated whether the prophylactic use of an implantable cardioverter-defibrillator (ICD) improves survival among patients who are at risk for sudden death due to left ventricular systolic dysfunction but who have not had a life-threatening ventricular arrhythmia. We assessed the cost-effectiveness of the ICD in the populations represented in these primary-prevention trials.
We developed a Markov model of the cost, quality of life, survival, and incremental cost-effectiveness of the prophylactic implantation of an ICD, as compared with control therapy, among patients with survival and mortality rates similar to those in each of the clinical trials. We modeled the efficacy of the ICD as a reduction in the relative risk of death on the basis of the hazard ratios reported in the individual clinical trials.
Use of the ICD increased lifetime costs in every trial. Two trials--the Coronary Artery Bypass Graft (CABG) Patch Trial and the Defibrillator in Acute Myocardial Infarction Trial (DINAMIT)--found that the prophylactic implantation of an ICD did not reduce the risk of death and thus was both more expensive and less effective than control therapy. For the other six trials--the Multicenter Automatic Defibrillator Implantation Trial (MADIT) I, MADIT II, the Multicenter Unsustained Tachycardia Trial (MUSTT), the Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE) trial, the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) trial, and the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT)--the use of an ICD was projected to add between 1.01 and 2.99 quality-adjusted life-years (QALY) and between 68,300 dollars and 101,500 dollars in cost. Using base-case assumptions, we found that the cost-effectiveness of the ICD as compared with control therapy in these six populations ranged from 34,000 dollars to 70,200 dollars per QALY gained. Sensitivity analyses showed that this cost-effectiveness ratio would remain below 100,000 dollars per QALY as long as the ICD reduced mortality for seven or more years.
Prophylactic implantation of an ICD has a cost-effectiveness ratio below 100,000 dollars per QALY gained in populations in which a significant device-related reduction in mortality has been demonstrated.
八项随机试验评估了对于因左心室收缩功能障碍而有猝死风险但未发生危及生命的室性心律失常的患者,预防性使用植入式心脏复律除颤器(ICD)是否能提高生存率。我们评估了ICD在这些一级预防试验所代表人群中的成本效益。
我们建立了一个马尔可夫模型,用于对比ICD预防性植入与对照治疗在成本、生活质量、生存率及增量成本效益方面的差异,模型中的患者生存率和死亡率与各临床试验中的情况相似。我们根据各单项临床试验报告的风险比,将ICD的疗效建模为死亡相对风险的降低。
在每项试验中,使用ICD都会增加终生成本。两项试验——冠状动脉旁路移植术(CABG)补片试验和急性心肌梗死试验中的除颤器(DINAMIT)试验——发现预防性植入ICD并未降低死亡风险,因此与对照治疗相比,既更昂贵又效果更差。对于其他六项试验——多中心自动除颤器植入试验(MADIT)I、MADIT II、多中心非持续性心动过速试验(MUSTT)、非缺血性心肌病治疗评估中的除颤器(DEFINITE)试验、心力衰竭中药物治疗、起搏和除颤的比较(COMPANION)试验以及心力衰竭中的心脏性猝死试验(SCD-HeFT)——预计使用ICD可增加1.01至2.99个质量调整生命年(QALY),成本增加68,300美元至101,500美元。使用基础情况假设,我们发现ICD与对照治疗相比,在这六个人群中的成本效益为每获得一个QALY 34,000美元至70,200美元。敏感性分析表明,只要ICD能降低死亡率七年或更长时间,该成本效益比将保持在每QALY 100,000美元以下。
在已证明ICD相关死亡率显著降低的人群中,预防性植入ICD的成本效益比低于每获得一个QALY 100,000美元。