Gekas Jean, Gagné Geneviève, Bujold Emmanuel, Douillard Daniel, Forest Jean-Claude, Reinharz Daniel, Rousseau François
Centre de recherche du CHUQ, Service de Génétique Médicale, Unité de Diagnostic Prénatal, Faculté de Médecine, Université Laval, Québec city, Québec, Canada.
BMJ. 2009 Feb 13;338:b138. doi: 10.1136/bmj.b138.
To assess and compare the cost effectiveness of three different strategies for prenatal screening for Down's syndrome (integrated test, sequential screening, and contingent screenings) and to determine the most useful cut-off values for risk.
Computer simulations to study integrated, sequential, and contingent screening strategies with various cut-offs leading to 19 potential screening algorithms.
The computer simulation was populated with data from the Serum Urine and Ultrasound Screening Study (SURUSS), real unit costs for healthcare interventions, and a population of 110 948 pregnancies from the province of Québec for the year 2001.
Cost effectiveness ratios, incremental cost effectiveness ratios, and screening options' outcomes.
The contingent screening strategy dominated all other screening options: it had the best cost effectiveness ratio ($C26,833 per case of Down's syndrome) with fewer procedure related euploid miscarriages and unnecessary terminations (respectively, 6 and 16 per 100,000 pregnancies). It also outperformed serum screening at the second trimester. In terms of the incremental cost effectiveness ratio, contingent screening was still dominant: compared with screening based on maternal age alone, the savings were $C30,963 per additional birth with Down's syndrome averted. Contingent screening was the only screening strategy that offered early reassurance to the majority of women (77.81%) in first trimester and minimised costs by limiting retesting during the second trimester (21.05%). For the contingent and sequential screening strategies, the choice of cut-off value for risk in the first trimester test significantly affected the cost effectiveness ratios (respectively, from $C26,833 to $C37,260 and from $C35,215 to $C45,314 per case of Down's syndrome), the number of procedure related euploid miscarriages (from 6 to 46 and from 6 to 45 per 100,000 pregnancies), and the number of unnecessary terminations (from 16 to 26 and from 16 to 25 per 100,000 pregnancies).
Contingent screening, with a first trimester cut-off value for high risk of 1 in 9, is the preferred option for prenatal screening of women for pregnancies affected by Down's syndrome.
评估并比较三种不同的唐氏综合征产前筛查策略（联合检测、序贯筛查和条件筛查）的成本效益，并确定最有用的风险临界值。
计算机模拟，研究具有不同临界值的联合、序贯和条件筛查策略，从而得出19种潜在的筛查算法。
计算机模拟采用了血清尿液和超声筛查研究（SURUSS）的数据、医疗干预的实际单位成本，以及2001年魁北克省110948例妊娠的数据。
成本效益比、增量成本效益比和筛查方案的结果。
条件筛查策略优于所有其他筛查方案：其成本效益比最佳（每例唐氏综合征病例26,833加元），与操作相关的整倍体流产和不必要终止妊娠的情况较少（分别为每100,000例妊娠6例和16例）。它在孕中期也优于血清筛查。就增量成本效益比而言，条件筛查仍然占主导地位：与仅基于母亲年龄的筛查相比，每多避免一例唐氏综合征患儿出生可节省30,963加元。条件筛查是唯一一种能在孕早期为大多数女性（77.81%）提供早期安心感，并通过限制孕中期的再次检测（21.05%）将成本降至最低的筛查策略。对于条件筛查和序贯筛查策略，孕早期检测中风险临界值的选择显著影响成本效益比（每例唐氏综合征病例分别从26,833加元到37,260加元，从35,215加元到45,314加元）、与操作相关的整倍体流产数量（每100,000例妊娠从6例到46例，从6例到45例）以及不必要终止妊娠的数量（每100,000例妊娠从16例到26例，从16例到25例）。
对于受唐氏综合征影响的妊娠女性进行产前筛查，首选的方案是条件筛查，其孕早期高风险临界值为1/9。
