全國性孕婦海洋性貧血篩檢計畫成果分析：醫療成本投入之觀點

Abstract

目的：政府早於1993年就開始實施全國性孕婦海洋性貧血篩檢計畫，希望能有效的減少重度甲型海洋性貧血胎兒對孕婦造成的合併症及重度乙型海洋性貧血病童的出生。降低重度乙型海洋性病患的醫療支出，讓有限的醫療資源獲得最大的效用。目前台灣大約有400位左右需要輸血的重度乙型海洋性貧血病患，分佈於全國各大醫學中心。我們希望完整調查篩檢的成果，了解篩檢計畫到底預防了多少病患出生？篩檢後還有多少病童出生？這個篩檢計畫是否可以降低整體的醫療成本？另外，有沒有其他的篩檢方式或補救措施，可以來改善我們現行的流程？這些方式的實施是否會比現行篩檢方式減少更多的醫療成本？ 方法：經由國民健康局及全國各大醫院小兒血液腫瘤科的協助，收集1994年之後(含1994年)出生之重度乙型海洋性貧血病患的個案數及出生原因。之後我們利用Hardy-Weinberg equation 來計算這些新生兒乙型海洋性貧血的帶原率；計算所得的帶原率本研究用來當作基礎值進一步估算篩檢支出。沒有實施篩檢計畫時支出的費用就是治療所有重度乙型海洋性貧血病患的醫療費用。而實施篩檢計畫時所帶來的費用就是耗用於篩檢計畫的所有花費再加上雖然有實施篩檢計畫，但卻生下來的漏網之魚的終身醫療費用。藉由有實施與沒有實施全國性孕婦海洋性貧血篩檢計畫所耗費醫療支出的差異本研究得以了解篩檢計畫的經濟效益。 結果：在1994年到2003年之間全國總共有97位重度乙型海洋性貧血病患出生。其中有8位病童的媽媽是外籍新娘；中國籍的有一位，印尼籍的有兩位，越南籍的有5位。最主要的出生原因是未能診斷出父母親可能是海洋性貧血帶原者 (54人)。經由 Hardy-Weinberg equation的運算，本研究成功的推估在1999到2003年間出生的小朋友乙型海洋性貧血的帶原率介於1.4到2.0%之間，平均是1.6%，高於以往報告的1.1%。在這段期間，全國性孕婦海洋性貧血篩檢計畫對重度乙型海洋性貧血的偵測率為68.5%，而且成功的防止了64.5%的病患出生。本研究也發現在1999到2003年之間，實施海洋性貧血篩檢計畫所需的總醫療支出比沒有實施篩檢計畫的醫療支出來的多。以4%的折現率來計算，則實施海洋性貧血篩檢計畫所需的支出會比沒有實施篩檢計畫多上新台幣230,518,886元。本研究認為現階段海洋性貧血篩檢計畫總支出費用之所以會居高不下的最主要原因是進入篩檢流程的男生太多；其中大部分是罹患缺鐵性貧血孕婦的先生。如果能排除或減少這些人進入篩檢流程就能減少新台幣186,282,156元的支出。 討論：本研究證實台灣的全國性孕婦海洋性貧血篩檢計畫有效的減少重度乙型海洋性貧血病人的出生率。但是仍有少數病童因篩檢失靈而出生；其中最主要的原因是未能偵測出父母親可能是海洋性貧血的帶原者，以致沒有進入或無法完成整個篩檢流程所致。由此可見，加強一般民眾及醫師本身對海洋性貧血的疾病知識將有助於減少病人的出生。另外，本研究發現，在像台灣一樣，甲、乙型海洋性貧血及孕婦缺鐵性貧血盛行率都偏高的地區實施全面性的孕婦海洋性貧血篩檢計畫不容易帶來經濟效益。一方面是減少重度甲型海洋性貧血胎兒對孕婦造成合併症的效益目前無法用金錢來評估；另一方面是為了維持篩檢的及時性及準確性，進入篩檢流程的男生實在太多；其中大部分是罹患缺鐵性貧血孕婦的先生。因此，先診斷出缺鐵性貧血，並將這些孕婦的先生排除於篩檢之外可以有效減少篩檢的費用。這個結果對與我國情況類似的地區，未來實施海洋性貧血篩檢計畫將有所啟發。

Background. A National Thalassemia Screening Program was adopted in Taiwan in 1993. However, the program’s results and impact were not known. The purpose of this study was to examine the results and determine if the program in Taiwan was cost-saving from a healthcare services perspective. Methods. Patients with β-thalassemia major born between 1994 and 2003 were recruited through the help of all thalassemia clinics in Taiwan. A structured questionnaire was designed to collect the reasons for affected births. The costs of healthcare services with and without the National Thalassemia Screening Program were compared. If total costs with the screening program were smaller than those without the screening program, the screening program was considered to be cost-saving. We adopted different assumptions regarding the key factors in the screening program to examine the marginal effects of these variables. Results. There were 97 affected births from 1994 to 2003.These births resulted after informed choice (n=4), screening problems (n=83), and undetermined causes (n=10). Approximately 83% (5/6) of affected births in 2003 came from interracial marriages. Underestimation of the cases with β-thalassemia major was revealed when the data obtained from Bureau of Health Promotion were compared with those we collected. Only data after 1999 are reliable and are used for cost analysis. The Hardy-Weinberg equation was used to calculate the carrier frequency. The total costs of healthcare services with and without the screening program under a 4% annual discount rate were US$ 16,124,044 and US$ 9,442,337, respectively for 50 years of follow-up. The screening program seemed not cost-saving. Conclusions. This report has identified several areas that might improve the thalassemia screening program, such as public education for both the public and general physicians, providing care of new female immigrants. The most important factor affecting the costsavings of the screening program was prevalence of and iron deficiency anemia (IDA) in pregnant women. In an area with high prevalence of α-, β-thalassemia, and IDA in pregnant women, excluding the male partners of pregnant women with IDA into screening would be helpful.