台灣1997至2002年高血壓藥物的用藥型態評估及當AIIA導入市場對臨床使用之影響

An evaluation on the pharmaceutical expenditure of antihypertensive agents during 1997 to 2002 and Impact of introduction of Angiotensin II Antagonist on the antihypertensive drug utilization in Taiwan

林銅祿(Tong-Lu Lin)

指導教授 ： 鄭慧文 ； 高雅慧

臺北醫學大學/藥學院/藥學研究所/博士(2007年)

https://doi.org/10.6831/TMU.2007.00108

摘要

利用健保局學術研究資料庫（National Health Insurance Academic Research Database；NHIARD），探討從1997年至2002年台灣高血壓藥物的用藥支付費用及型態，並評估當新的高血壓藥物類別血管張力素II 拮抗劑（Angiotensin II Antagonist；AIIA）導入市場後，對原有高血壓藥物使用行為所造成的影響；特別是針對台灣市場佔有率最高的血管收縮素轉換酶抑制劑（Angiotensin Converting Enzyme Inhibitors；ACEI）、乙型腎上腺素阻斷劑（β- Blockers；BB）、鈣離子阻斷劑（Calcium Channel Blockers；CCB）及其他類別Miscellaneous agents(MIS)等，四大類高血壓藥物。
從健保資料庫（NHIARD）取得1997年至2002年高血壓用藥資料，包括門診病例記錄及用藥處方資料，藥物支付費用可分成5個部份，包括相關的藥物價格、病患人數、每位病患的就醫平均數、每位醫師看診病歷處方中的每日劑量及殘餘值；同時並取得病患的病歷檔案（Medication profile）、醫院看診記錄（Hospital visit record）及藥品申報資料（Drug claim data），執行評估高血壓用藥的申報金額、臨床使用量、處方情形與病患市場佔有率分析等等，藉以瞭解當AIIA導入市場後，對高血壓藥物ACEI、BB和CCB及MIS等類別所造成的影響，本研究將以市場佔有率表示各類別高血壓藥物間的市場相對強度，包括：支付金額市場佔有率、臨床市場佔有率、處方數量市場佔有率、病患人數市場佔有率，同時並探討AIIA對不同層級醫院用藥的滲透時間。
1997年至2002年總高血壓用藥增加102%，主要的成因是混合效應－從病患人數增加34%，醫師看診病歷處方中每位病患的每日劑量增加33%，而高血壓用藥總殘餘值因素僅有7%的影響。此結果與瑞典、西班牙兩國經驗有所不同，其藥物支付費用之增加主要是來自於殘餘值。詳細的殘餘值分析顯示：原廠品牌的類別產品有11%的成長，但一般學名藥卻減少12%。至於醫院的殘餘值：醫學中心成長13%、區域醫院成長17%、地區醫院成長10%，但基層醫療診所卻下降14%。此結果顯示，各層級醫院醫師有不同的處方用藥行為，醫院層級醫師的用藥行為偏向新藥或原開發廠品牌藥，基層醫療醫師則傾向使用一般學名藥。至於，高血壓藥物各類別於支付金額市場佔有率、臨床市場佔有率、處方數市場佔有率、病患人數市場佔有率的分析上，當AIIA導入市場後，對其他高血壓藥物ACEI、BB、CCB和MIS所造成的影響。研究結果顯示，AIIA對ACEI影響最大，這是由於藥理性質相類似所造成的結果，AIIA對BB僅有小部份的影響，對CCB無影響且有正面加分作用，MIS則漸被淡忘。AIIA市場上的成長，最主要的原因是來自於取代ACEI及與其他高血壓藥物一起服用的併服療法，尤其是與CCB和BB併服後讓CCB維持成長BB流失不多。AIIA於各層級醫院以臨床市場佔有率及處方數量市場佔有率的成長強度分析依：醫學中心、區域醫院、地區醫院、基層醫療依序為：4.95：3.77：2.77：1及5.28：4.17：2.94：1。可知，醫學中心＞區域醫院＞地區醫院＞基層醫療。
高血壓藥物支付費用成長的重要原因是病患人數及醫師門診處方中DDDS值的增加所致，各層級醫師有不同的處方用藥行為，醫院層級醫師的用藥行為偏向新藥或原開發產的品牌藥，基層醫療醫醫師則傾向使用一般學名藥。CCB是目前高血壓用藥的主流雖有小成長但再成長有限，AIIA呈現持續成長的趨勢，BB雖微下滑但維持平穩，ACEI有被AIIA取代現象僅以大量價格低廉之學名藥維持其數量上之優勢，MIS已漸被淡忘。由於醫院層級醫師用藥行為偏向新藥及品牌藥，所以醫學中心對AIIA的利用與擴散具有關鍵性之角色。

關鍵字

藥物經濟學 ； 藥物使用量 ； 殘餘值 ； 每日劑量 ； 血管張力素II 拮抗劑 ； 市場佔有率

並列摘要

Background and Purpose
Antihypertensive medications have represented a tremendous financial burden to the health care plan globally. This study examined the utilization pattern of the antihypertensive agents to analyze the underlying reasons responsible for the pharmaceutical expenditure in Taiwan during 1997 to 2002 as well as to evaluate the long term impact of a new pharmacological class antihypertensive medicine- angiotensin II antagonist (AIIA) to the clinical utilization of the existing antihypertensive medications in Taiwan.
Methods
The claims data during 1997 to 2002 were obtained from National Health Insurance Academic Research Database (NHIARD), which include ambulatory service record and prescription data of the entire population. Drug expenditure was decomposed into 5 components: relative drug price, number of patients treated, average physician visit per patient, Defined Daily Dose (DDD) per physician visit and a residual. Gross growth of DDD and prescription numbers, market share analysis including monetary market share (MMS), clinical market share (CMS), prescription market share (PrMS) and patient market share (PtMS), market penetration time and DDDs/ prescription were used to assess AIIA's impact on the angiotensin converting enzyme inhibitors (ACEI), β- Blockers (BB), calcium channel blockers (CCB) and other miscellaneous antihypertensive agents (MIS).
Result
Total antihypertensive drug spending increased 102% during this period, mainly due to the compounding effect from the increment of patients treated (34%) and DDD per physician visit (33%). Residual analysis revealed that the aggregate residual for antihypertensive agents only had a 7% effect; the brand- name product had 11% increment and the generic product had a 12% decrement. It also showed that while hospital sector had a positive 11% residual, primary care clinics had an 11% decrement. Detailed analysis on each sub- group revealed that CCB had the most significant gross growth of DDDs and prescription at 117.1 and 3.4 million increments, respectively. CMS results revealed that the introduction of AIIA had the most significant impact to the clinical utilization of MIS (-5.5%) and a moderate impact to both BB (-4.5%) and ACEI (-4.1%). Whereas PMS demonstrated the most significant impact to MIS (-6.5%), a moderate impact to ACEI (-2.3%) and a very minor impact to BB (-0.9%). AIIA, however, had a positive CMS (+3.9%) and PMS (+2.4%) correlation with CCB. AIIA utilization implicated by relative growth strength for the CMS and PMS at Medical Center, Regional Hospital, District Hospital and Primary Care Clinic were 4.95 : 3.77 : 2.77 : 1 and 5.28 : 4.17 : 2.94 : 1, respectively.
Conclusion
The most important factors that contribute to the expenditure surge of antihypertensive agents are number of treated patients and DDD per physician visit. While physicians at the hospital sector adopted more new and innovative medications, their counterpart at the primary care clinics tended to switch some off- patent products to the generics. The introduction of AIIA did not affect the negative clinical utilization drift of MIS and BB since this depressing trend started before AIIA introduction. On the other hand, the preference of using CCB and AIIA to control hypertension among the physicians in Taiwan was on the ascending side. Medial center was the early leading adaptor for AIIA and furthermore played an important role in the utilization diffusion of AIIA.

並列關鍵字

Antihypertensive agent ； Defined daily dose (DDD) ； Drug utilization ； Pharmaceutical expenditure ； Angiotensin II antagonist (AIIA) ； Angiotensin converting enzyme inhibitor (ACEI) ； &szlig ； - blocker (BB) ； Calcium channel blocker (CCB) ； Market share

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