抗血小板藥物用於預防中風復發之成本效果分析-以台灣為例

Cost-Effectiveness Analysis of Antiplatelet Therapy in the Prevention of Recurrent Stroke in Taiwan

張雅婷(Ya-Ting Chang)

指導教授 ： 許光陽

共同指導教授 ： 簡淑真

臺北醫學大學/藥學院/藥學研究所/碩士(2007年)

摘要

研究目的：
目前臨床上用來預防缺血性中風復發的藥物以抗血小板藥物為主。早期，aspirin是抗血小板藥物之中減少此類型中風復發的第一選擇。近年來，開始有其他的抗血小板藥物問世，包含clopidogrel以及新的複方抗血小板藥物：aspirin加上modified-release dipyridamole。然而這些新藥的價格都比aspirin來得昂貴，且台灣目前尚未有相關的藥物經濟學研究，因此有進行這類藥品成本效果分析之必要。故本研究將採用台灣資料來探討使用新的抗血小板藥物是否符合成本效益。

研究方法：
藉由二年馬可夫模式，以台灣健保局觀點進行成本效果分析。研究對象為65歲以上曾經發生過一次缺血性中風的病患。欲分析的藥物有aspirin，clopidgorel，以及aspirin加上modified-release dipyridamole(簡稱ASA+MR-DP)。以上三項藥品將進行兩兩組間比較，探討使用何者藥品比較符合成本效益。主要測量的結果變項為生活品質校正年(Quality-adjusted life-year, QALY)。

研究結果：
兩年初步分析結果顯示，使用ASA+MR-DP病患的生活品質校正年為1.948年，成本花費為45,310元；而使用aspirin病患的生活品質校正年為1.946年，成本花費為33,623元；兩者的邊際效益比值(ICER)為1,889,544元/QALY。使用clopidogrel病患的生活品質校正年為1.948年，成本花費為68,334元，與aspirin相比之後的邊際效益比值為9,699,399元/QALY。進行單維敏感性分析時發現，變項為「抗血小板藥物對於預防中風復發的效果」以及「抗血小板藥物藥價」，此兩項變項的改變會造成邊際效益比值變化甚大，進而可能影響研究結論之改變。

結論：
本研究結果顯示使用任一新型抗血小板藥物與aspirin相比，均可有較長的生活品質校正年(QALY)，且有較高的醫療成本花費，屬於cost-effective。但醫療決策者是否願意支付更高的醫療成本來得到一個生活品質校正年，需要更多的相關數據及參考文獻來進行相關決策。

關鍵字

缺血性腦中風 ； aspirin ； clopidogrel ； aspirin plus modified-release dipyridamole ； 馬可夫模式 ； 成本效果分析 ； 生活品質校正年

並列摘要

Background：
Antiplatelet agents can prevent recurrent stroke. Aspirin is the most widely studied one and, until recently, it was the only drug used broadly for this purpose. Now, clinical trials indicate that ticlopidine, clopidogrel, and a combination regimen, aspirin plus modified-release dipyridamole (ASA+MR-DP), are also effective for prevention of recurrent stroke. However, these new antiplatelet agents are more expensive than aspirin. In Taiwan, their cost-effectiveness ratios relative to aspirin have not been estimated.

Method：
Markov model is developed to measure the clinical benefit and economic consequences of the following strategies to treat high-risk patients aged 65 years or older: (1) aspirin 100mg once a day; (2) aspirin 25mg plus modified-release dipyridamole 200mg (ASA+MR-DP) twice a day; and (3) clopidogrel 75mg once a day. Input data were obtained from literature review. Cost and quality-adjusted life-year (QALY) are primary outcomes measured. The time frame is two years.

Results：
The use of aspirin combined with dipyridamole was slightly effective and more costly compared the use of aspirin: direct cost per one patient is NTD 45,310, and estimated QALY for one patient is 1.948 years; in aspirin group: direct cost per one patient is NTD 33,623, and estimated QALY for one patient is 1.946 years. The Incremental cost-effectiveness ratio (ICER) between aspirin and ASA+MR-DP is NTD 1,889,544 per QALY. The comparison between aspirin and clopidogrel: The incremental cost-effectiveness ratio between aspirin and clopidogrel is NTD 9,699,399 per QALY. In sensitivity analyses, the efficacy and drug prices of antiplatelet agents are key factors to determine the ICER compared with aspirin.

Conclusion：
Comparing new antiplatelet agents to aspirin, our results show that using new drugs is cost-effective, it means using new drug has better outcome, but induces highly medical direct cost.

並列關鍵字

ischemic stroke ； aspirin ； clopidogrel ； aspirin plus modified-release dipyridamole ； Markov model ； cost-effectiveness analysis ； quality-adjusted life year

參考文獻

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