Antenatal screening for Down's syndrome.
Antenatal screening for Down's syndrome.
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唐氏综合症产前筛查。
DOI：
10.1136/bmj.305.6856.768
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发表时间：
1992
影响因子：
--
通讯作者：
T. Clift
中科院分区：
文献类型：
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作者：
T. Clift
编辑，尼古拉斯·J·沃尔德（Nicholas J Wald）及其同事的示范项目意味着，对于孕妇唐氏综合症的“三重测试”筛查，没有什么可以证明的了，剩下的就是立即在全国范围内引入该测试。正如最近的信件所示，这是我和其他人感到不满意的前提。23 Wald 及其同事报告了通过三重测试对 12 603 名女性进行筛查的结果，该人群的检出率为 48%。确实，这个数字很小（12/25），但这远低于之前建议的 58%。4 该论文根本没有提及未接受筛查的 26% 女性。如果论文中讨论的 12,603 名女性中有 74% 接受了血液检查，那么所研究的总人口就有 17031 名女性。因为我们没有关于其他 4428 名女性的人口统计特征或她们怀孕结果的信息，所以我只能假设她们怀孕期间唐氏综合症的发病率与筛查人群中的相同。因此，结论必定是研究人群中约有 34 名怀孕者患有唐氏综合症。这一数字将整个怀孕人群的检出率降低至 35-3%，并将已知的唐氏分娩预防措施（大概是期望的结果）降低至 26-5%。此外，筛查人群的双向表使三重检验的阳性预测值仅为 2-3%，该数字远低于任何筛查方法所需的值。在此基础上，必须再次询问全面引入三重检测筛查是否适当或有效。尽管沃尔德及其同事的论文声称，但实际上并没有表明唐氏综合症的发生率会进一步降低。这项计划对孕妇造成的心理成本可能是巨大的5：17 031 人不得不考虑进行检查，12 603 人不得不等待结果，514 人接受羊膜穿刺术。我们不知道流产率。从最近的信件7来看，作者在成本效益分析中使用的成本计算可能被低估了。由于为所有女性提供咨询都会产生费用，因此当考虑到整个人口而不仅仅是那些接受筛查的人时，成本效益分析看起来更不利。
EDITOR,-Nicholas J Wald and colleagues' demonstration project' implies that there is nothing left to prove with regard to the "triple test" screening of pregnant women for Down's syndrome, and that all that remains is for the test to be introduced on a national level immediately. This is a premise I and others feel unhappy about, as recent correspondence has shown.23 Wald and colleagues report the results of screening 12 603 women with the triple test, achieving a detection rate of 48% in that population. It is true that the numbers are small (12/25), but this is considerably below the 58% previously suggested.4 The paper does not refer at all to the 26% ofwomen not screened. If the 12 603 women discussed in the paper were the 74% who had the blood test, the total population under study therefore comprised 17031 women. Because we have no information about the demographic characteristics of the other 4428 women, or the outcomes of their pregnancies, I can only assume that the rate of Down's syndrome in their pregnancies was the same as in the screened population. Thus, the conclusion must be that some 34 pregnancies in the study population were affected with Down's syndrome. This figure reduces the detection rate for this pregnant population as a whole to 35-3% and the known prevention of Down's births (presumably the desired outcome) to 26-5%. Additionally, a two way table for the screened population gives the triple test a positive predictive value of only 2-3%, a figure well below that required for any method of screening. On this basis, it must again be asked whether the wholesale introduction of triple test screening is either appropriate or effective. Wald and colleagues' paper certainly does not show, despite its claims, that the incidence of Down's births will be reduced much further in practice. It is probable that the psychological costs of this programme to pregnant women will be enormous5: 17 031 had to consider the test, 12 603 had to wait for results, and 514 undergo amniocentesis. We are not told the miscarriage rate. It also seems from recent correspondence' 7 that the costings used by the authors for their cost effectiveness analysis are probably an underestimate. As there are costs incurred through counselling for all women, the cost effectiveness analysis looks even less favourable when the whole population, rather than only those who are screened, is considered.