未破裂脳動脈瘤のコイル塞栓術適応に関する医療経済学的な考察

抄録

The purpose of this study was to determine an optimal treatment strategy between coil embolization and non-surgical treatment for unruptured cerebral aneurysm from a cost-effectiveness point of view. With a Markov model and Monte-Carlo simulation, we compared coil embolization with non-surgical treatment in patients with an unruptured cerebral aneurysm. We varied the patient age range between 50 and 85 years with an interval of 5 years. We also varied the rupture rate of aneurysm between 0.5% and 3.5% per year with an interval of 0.5%. A simulation cycle was repeated until 99.9% of the patients changed to a dead status. To analyze the impact on costs and quality-adjusted life-year (QALY), a threshold of incremental cost-effectiveness ratio (ICER) was set to 5,000,000 yen and 3,000,000 yen, respectively, representing the standard criteria of Japan and United Kingdom. With an estimated aneurysmal rupture rate of 1.0%, 1.5%, and 2.0% per year, coil embolization was more cost-effective in male patients under 68, 74, and 78 years age and female patients under 71, 77, and 81 years of age, respectively. Assuming that the utility health value of non-surgical patients with a rupture rate of 1.0% per year decreases from 1 to 0.95, coil embolization was more cost-effective in male patients under 79 years and in female patients under 81 years.