Amin Alpesh, Stokes Michael, Makenbaeva Dinara, Wiederkehr Daniel, Wu Ning, Lawrence John H
University of California , Irvine, CA , USA.
J Med Econ. 2014 Nov;17(11):771-81. doi: 10.3111/13696998.2014.953682. Epub 2014 Aug 26.
RESULTS of randomized clinical trials (RCT) demonstrate that novel oral anticoagulants (NOAC) are effective therapies for reducing the risk of stroke in non-valvular atrial fibrillation (NVAF). Prior medical cost avoidance studies have used warfarin event rates from RCTs, which may differ from patients receiving treatment in a real-world (RW) setting, where the quality of care may not be the same as in a RCT. The purpose of this study was to estimate the change in medical costs related to stroke and major bleeding for each NOAC (apixaban, dabigatran, and rivoraxaban) relative to warfarin in a RW NVAF population.
Patients (n = 23,525) with a diagnosis of NVAF during 2007-2010 were selected from a Medco population of US health plans. Stroke and major bleeding excluding intracranial hemorrhage (MBEIH) events were identified using diagnosis codes on medical claims. RW reference event rates were calculated during periods of warfarin exposure. RW event rates for NOACs were estimated by multiplying the corresponding relative risk (RR) from the RCTs by each reference rate. Absolute risk reductions (ARR) or number of events avoided per patient year were then estimated. Changes in medical costs associated with each NOAC were calculated by applying the ARR to the 1-year cost for each event. Costs for stroke and MBEIH were obtained from the literature. Drug and international normalized ratio monitoring costs were not considered in this analysis.
Compared to RW warfarin, use of apixaban and dabigatran resulted in total (stroke plus MBEIH) medical cost reductions of $1245 and $555, respectively, during a patient year. Rivaroxaban resulted in a medical cost increase of $144.
If relative risk reductions demonstrated in RCTs persist in a RW setting, apixaban would confer the greatest medical cost savings vs warfarin, resulting from significantly lower rates of both stroke and MBEIH.
随机临床试验（RCT）结果表明，新型口服抗凝药（NOAC）是降低非瓣膜性心房颤动（NVAF）患者中风风险的有效疗法。先前的医疗成本规避研究使用了RCT中的华法林事件发生率，这可能与现实世界（RW）环境中接受治疗的患者不同，在现实世界中，医疗质量可能与RCT中的情况不一样。本研究的目的是估计在RW NVAF人群中，相对于华法林，每种NOAC（阿哌沙班、达比加群和利伐沙班）与中风和大出血相关的医疗成本变化。
从美国健康计划的Medco人群中选取2007 - 2010年期间诊断为NVAF的患者（n = 23525）。使用医疗索赔中的诊断代码确定中风和不包括颅内出血的大出血（MBEIH）事件。在华法林暴露期间计算RW参考事件发生率。通过将RCT中的相应相对风险（RR）乘以每个参考率来估计NOAC的RW事件发生率。然后估计绝对风险降低率（ARR）或每位患者每年避免的事件数。通过将ARR应用于每个事件的1年成本来计算与每种NOAC相关的医疗成本变化。中风和MBEIH的成本来自文献。本分析未考虑药物和国际标准化比值监测成本。
与RW华法林相比，在患者一年中，使用阿哌沙班和达比加群分别使总（中风加MBEIH）医疗成本降低了1245美元和555美元。利伐沙班使医疗成本增加了144美元。
如果RCT中显示的相对风险降低在RW环境中持续存在，与华法林相比，阿哌沙班将带来最大的医疗成本节省，这是由于中风和MBEIH的发生率显著降低。
