Romano P S, Waitzman N J
Department of Medicine, University of California, Davis 95817, USA.
Ann N Y Acad Sci. 1998 Jun 18;847:154-72. doi: 10.1111/j.1749-6632.1998.tb08936.x.
Decision analysis is a widely used tool to improve clinical decision making when randomized controlled trials are infeasible, underpowered, or lack generalizability. We performed an exploratory decision analysis of routine second trimester ultrasound to detect fetal anomalies, focusing on the assumptions that would have the greatest impact. Six outcome categories were considered: (1) abnormal ultrasound, anomalous child, (2) abnormal ultrasound, elective abortion of anomalous fetus, (3) abnormal ultrasound, healthy child, (4) abnormal ultrasound, elective abortion of healthy fetus, (5) normal ultrasound, healthy child, and (6) normal ultrasound, anomalous child. Live birth and fetal death rates for nine sonographically detectable anomalies were obtained from the California Birth Defects Monitoring Program. The sensitivity and specificity of ultrasound were estimated through meta-analysis of recent series. Plausible ranges for the probabilities of cesarean delivery and elective abortion, by anomaly, were determined through review of the literature. Standard gamble, willingness-to-pay, and human capital estimates of utility were rescaled for comparability. We found that routine ultrasound appears to be the preferred strategy for most women. This choice is sensitive primarily to the specificity of ultrasound and women's willingness-to-pay for the reassurance of a normal ultrasound.
当随机对照试验不可行、效力不足或缺乏普遍性时，决策分析是一种广泛用于改善临床决策的工具。我们对孕中期常规超声检查以检测胎儿异常进行了探索性决策分析，重点关注那些具有最大影响的假设。考虑了六个结果类别：（1）超声异常，胎儿异常；（2）超声异常，选择性终止异常胎儿妊娠；（3）超声异常，胎儿健康；（4）超声异常，选择性终止健康胎儿妊娠；（5）超声正常，胎儿健康；（6）超声正常，胎儿异常。从加利福尼亚出生缺陷监测项目获得了九种超声可检测异常的活产率和胎儿死亡率。通过对近期系列研究的荟萃分析估计了超声的敏感性和特异性。通过文献回顾确定了按异常情况划分的剖宫产和选择性堕胎概率的合理范围。对标准博弈、支付意愿和人力资本效用估计值进行了重新调整以使其具有可比性。我们发现常规超声似乎是大多数女性的首选策略。这一选择主要对超声的特异性以及女性为获得超声正常的安心感而支付的意愿敏感。
