[[alternative]]Cost-effectiveness Analyses of Drug-eluting Versus Bare-metal Stents

[[abstract]]近年來，支架置放術已成爲冠狀動脈疾病治療方式的主流，其中，塗藥支架(drug-elutingstent)因可降低傳統支架(bare-metal stent)引起的病灶再重建(target lesion revascularization; TLR)比率，自推出之後便廣爲運用，然而其較高的初期治療成本不禁會讓人質疑其是否符合成本效益。本研究以回溯性研究法分析自2003年11月至2005年3月因冠狀動脈疾病入院接受支架置放術之連續病患，經處置後追蹤滿36個月之354人；其中傳統支架組有171人，而塗藥支架組有183人。本研究透過長期追蹤，研究這些患者的臨床數據和與治療冠狀動脈相關之費用結構及其相關因素。本研究使用客觀叢集分析方法(objective cluster analysis technique)尋找出適當的分組方式，再運用增加成本效益比(incremental cost-effectiveness ratio; ICER)技術計算其在減少病灶再重建上的成本效益，藉以找出較適合使用塗藥支架之患者族群。塗藥支架組與傳統支架組術後追蹤至36個月的死亡率及復發非致死性心肌梗塞率兩組並無顯著差異；病灶再重建次數塗藥支架組顯著少於傳統支架組（9.9%比25.0%，P=0.001）。在醫療費用方面，雖然塗藥支架組術後的三年醫療費用較傳統支架組高，但扣除接受支架置放術當次住院的支架耗材費用後，其後續醫療費用有較低的趨勢。而塗藥支架的增加成本效益比爲－595K（95%CI爲－237K~-950K）（仟元台幣），符合世界衛生組織之規範標準，亦即使用塗藥支架，平均三年內每減少一個病灶再重建需要花費595，000元。在叢集分析結果方面，發現只要下列三項條件具備至少一項時，使用塗藥支架便具有成本效益：曾接受冠狀動脈介入性治療、有相關心血管疾病以及有糖尿病。塗藥支架雖然初期的治療成本雖較傳統支架高，然而其對降低後續醫療費用應屬有效，尤其是對上述特定的高風險族群。[[abstract]]Drug-eluting stents (DES) used to treat coronary lesions reduce rates of target lesion revascularization compared to bare-metal stents (BMS). Drug-eluting stents, however, are considerably more expensive than BMS. The aim of this study was to evaluate whether DES are a cost-effective alternative for BMS. We retrospectively analyzed the clinical data and the medical costs of 354 patients with coronary artery disease undergoing coronary stenting from Nov. 2003 to Mar. 2005 from our electronic database. Among the 354 patients, 171 (48%) underwent stenting with BMS and 183 (52%) underwent DES stenting. The major adverse cardiac events regarding mortality, recurrent non-fatal myocardial infarction, and target lesion revascularization (TLR) were recorded and economic analyses were performed using incremental cost-effectiveness ratio (ICER) method and objective cluster analysis technique. During a follow-up of 36 months, using DES instead of BMS does not affect survival or recurrent nonfatal myocardial infarctions. However, the incidence of TLR was significantly lower in the DES group compared to the BMS group (9.9% vs. 25.0%, P = 0.001). As to the cost-effectiveness analyses, although the initial medical costs were significant higher in the DES group, there was a trend toward reduction in medical costs during followup as compared to those of the BMS group. In our analysis, the overall incremental cost-effectiveness ratio was NT$ -595K (95% CI:-237K~-950K) per TLR reduced, indicating that DES may be cost effective. Furthermore, using objective cluster analysis technique, the following high-risk groups that will benefit from DES were identified: patients with prior coronary interventions, patients with prior cardiovascular disease other than coronary artery disease, and diabetic patients. Although the initial medical costs were significant higher in the DES group, the cost-effectiveness of DES may be favorable in comparison with BMS at 36 months. Our data also demonstrated that the use of DES would be best targeted at the subgroups of patients with the higher risks of requiring reintervention