Abstract：
OBJECTIVE: Noninvasive prenatal testing (NIPT) has increased the number of conditions that can be screened. However, the prevalence of conditions assessed by NIPT has remained stable. The \"prevalence threshold,\" a novel epidemiological concept, uses a test\'s sensitivity and specificity to determine the prevalence below which a test\'s positive predictive value declines most sharply relative to disease prevalence. In this article, we calculated the prevalence threshold for common conditions assessed through NIPT and compared the value with the actual prevalence of each condition to best ascertain the reliability of NIPT results.
METHODS: Six databases and PubMed were searched from January 2010 to March 2023 for sensitivity and specificity parameters of common conditions tested through NIPT. Using an equation previously derived by the authors of the current paper, the prevalence threshold for each condition was calculated. The theoretical number of test iterations required to reach the prevalence threshold was also reported.
RESULTS: None of the conditions tested through the NIPT had a prevalence rate that met or exceeded the calculated prevalence threshold. Trisomy 21 had the greatest concordance between the prevalence rate and the prevalence threshold. In contrast, Angelman, Cri-du-chat, and Prader-Willi syndromes had the most significant discordance. Apart from trisomy 21 and XXY, all remaining conditions required more than one test iteration to reach their respective prevalence threshold.
CONCLUSIONS: We conclude that at the current prevalence levels, the positive predictive value of NIPT remains low, with the prevalence of disease levels significantly lower than the prevalence threshold for each condition tested.
METHODS: Six databases and PubMed were searched from January 2010 to March 2023 for sensitivity and specificity parameters of common conditions tested through NIPT. Using an equation previously derived by the authors of the current paper, the prevalence threshold for each condition was calculated. The theoretical number of test iterations required to reach the prevalence threshold was also reported.
RESULTS: None of the conditions tested through the NIPT had a prevalence rate that met or exceeded the calculated prevalence threshold. Trisomy 21 had the greatest concordance between the prevalence rate and the prevalence threshold. In contrast, Angelman, Cri-du-chat, and Prader-Willi syndromes had the most significant discordance. Apart from trisomy 21 and XXY, all remaining conditions required more than one test iteration to reach their respective prevalence threshold.
CONCLUSIONS: We conclude that at the current prevalence levels, the positive predictive value of NIPT remains low, with the prevalence of disease levels significantly lower than the prevalence threshold for each condition tested.
摘要：
目的：非侵入性产前检测（NIPT）增加了可以筛查的条件数量。然而,NIPT评估的疾病患病率保持稳定.“患病率阈值，“一个新的流行病学概念，使用测试的敏感性和特异性来确定患病率，在该患病率下，测试的阳性预测值相对于疾病患病率下降幅度最大。在这篇文章中,我们计算了通过NIPT评估的常见病症的患病率阈值,并将该值与每种病症的实际患病率进行比较,以最好地确定NIPT结果的可靠性.
方法：从2010年1月至2023年3月，在六个数据库和PubMed中搜索了通过NIPT测试的常见条件的敏感性和特异性参数。使用本文作者先前推导的方程，计算每种情况的患病率阈值.还报告了达到流行阈值所需的理论测试迭代次数。
结果：通过NIPT测试的所有条件的患病率均未达到或超过计算的患病率阈值。21三体在患病率和患病率阈值之间具有最大的一致性。相比之下,Angelman,Cri-du-chat,和Prader-Willi综合征有最显著的不一致。除了21三体和XXY，所有剩余条件需要多次测试迭代才能达到各自的患病率阈值.
结论：我们得出结论，在目前的患病率水平下，NIPT的阳性预测值仍然很低，在每个测试条件下，疾病水平的患病率显着低于患病率阈值。
方法：从2010年1月至2023年3月，在六个数据库和PubMed中搜索了通过NIPT测试的常见条件的敏感性和特异性参数。使用本文作者先前推导的方程，计算每种情况的患病率阈值.还报告了达到流行阈值所需的理论测试迭代次数。
结果：通过NIPT测试的所有条件的患病率均未达到或超过计算的患病率阈值。21三体在患病率和患病率阈值之间具有最大的一致性。相比之下,Angelman,Cri-du-chat,和Prader-Willi综合征有最显著的不一致。除了21三体和XXY，所有剩余条件需要多次测试迭代才能达到各自的患病率阈值.
结论：我们得出结论，在目前的患病率水平下，NIPT的阳性预测值仍然很低，在每个测试条件下，疾病水平的患病率显着低于患病率阈值。
