Smith Dean G, Nguyen Anh B, Peak Corey N, Frech Feride H
Department of Health Management and Policy, School of Public Health, University of Michigan, Ann Arbor 48109, USA.
J Manag Care Pharm. 2004 Jan-Feb;10(1):26-32. doi: 10.18553/jmcp.2004.10.1.26.
To estimate 8-year health and economic outcomes of the angiotensin II receptor blocker valsartan versus the calcium channel blocker amlodipine in therapy of patients with type 2 diabetes and microalbuminuria based on clinical endpoints from a 6-month randomized controlled clinical trial, the MicroAlbuminuria Reduction With VALsartan (MARVAL) study.
We developed a Markov model that utilized urinary albumin excretion rate data to project patient distributions to 7 possible health states over 8 years. For each health state, we identified quality-adjustment weights (health utilities) and medical care costs from public sources. The model then calculated mean quality-adjusted survival, medical care costs, and cost-effectiveness ratios for each treatment arm. Treatment arms were compared with the incremental cost-effectiveness ratio.
Patients treated with valsartan gained 7 months (mean) per patient of quality-adjusted survival relative to patients treated with amlodipine (77 versus 70 months; P<0.01); valsartan patients also incurred 32,412 dollars (mean) per patient lower medical costs than amlodipine patients (92,058 dollars versus 124,470 dollars; P<0.01). Model results were consistent for each year of analysis and robust to changes in key model parameters.
This research (1) extends 6-month clinical trial outcomes to an 8-year period, (2) translates health outcomes from technical clinical endpoints to quality-adjusted survival, and (3) estimates economic consequences of therapeutic outcomes. The results quantify the favorable long-term health (i.e., quality-adjusted survival) and economic benefits (i.e., lower total medical costs) of therapy with valsartan, an angiotensin II receptor blocker, versus amlodipine, a calcium channel blocker, in the treatment of patients with type 2 diabetes and microalbuminuria based on an extension of the results of a short-term clinical (MARVAL) trial. These research findings are important to the extent patients with type 2 diabetes and microalbuminuria do not receive the recommended antihypertensive agents that block the renin-angiotensin system (angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers).
基于一项为期6个月的随机对照临床试验“缬沙坦降低微量白蛋白尿（MARVAL）研究”的临床终点，评估血管紧张素II受体阻滞剂缬沙坦与钙通道阻滞剂氨氯地平治疗2型糖尿病合并微量白蛋白尿患者的8年健康和经济结局。
我们构建了一个马尔可夫模型，利用尿白蛋白排泄率数据预测患者在8年内分布于7种可能健康状态的情况。对于每种健康状态，我们从公共来源确定质量调整权重（健康效用）和医疗费用。然后该模型计算每个治疗组的平均质量调整生存期、医疗费用和成本效益比。通过增量成本效益比比较各治疗组。
与接受氨氯地平治疗的患者相比，接受缬沙坦治疗的患者每人获得了7个月（平均）的质量调整生存期（77个月对70个月；P<0.01）；缬沙坦治疗的患者每人的医疗费用也比氨氯地平治疗的患者低32412美元（平均）（92058美元对124470美元；P<0.01）。模型结果在每年的分析中都是一致的，并且对关键模型参数的变化具有稳健性。
本研究（1）将6个月的临床试验结果扩展至8年，（2）将健康结局从技术临床终点转化为质量调整生存期，（3）估计治疗结局的经济后果。结果量化了血管紧张素II受体阻滞剂缬沙坦与钙通道阻滞剂氨氯地平相比，在治疗2型糖尿病合并微量白蛋白尿患者方面的长期健康益处（即质量调整生存期）和经济效益（即更低的总医疗费用），这是基于一项短期临床（MARVAL）试验结果的扩展。这些研究结果对于2型糖尿病合并微量白蛋白尿患者未接受推荐的阻断肾素-血管紧张素系统的抗高血压药物（血管紧张素转换酶抑制剂或血管紧张素II受体阻滞剂）的情况具有重要意义。
