Shrout P E, Newman S C
Division of Biostatistics, Columbia University School of Public Health, New York, New York 10032.
Biometrics. 1989 Jun;45(2):549-55.
Two-phase medical surveys, in which a large sample is assessed with an inexpensive screening instrument and a subsample is selected for a more thorough diagnostic evaluation, appear to have great merit in the epidemiologic study of certain rare disorders. We present the optimal design of two-phase surveys when resources are fixed and when 100% of those screened positive in the first phase must be included in the second-phase evaluation. We go on to examine the relative efficiency of this two-phase design compared to a single-phase design in which all resources are used in a survey that employs the diagnostic evaluation. Given information on the accuracy of the screen and the prevalence of the disorder, the utility of the two-phase design depends on the relative cost of the screening to the diagnostic assessments.
两阶段医学调查，即在第一阶段使用低成本筛查工具对大样本进行评估，并在第二阶段选择一个子样本进行更全面的诊断评估，在某些罕见疾病的流行病学研究中似乎具有很大的优势。我们给出了在资源固定且第一阶段筛查呈阳性的所有人都必须纳入第二阶段评估的情况下两阶段调查的最优设计。接着，我们考察了这种两阶段设计与单阶段设计（即在采用诊断评估的调查中使用所有资源）相比的相对效率。给定有关筛查准确性和疾病患病率的信息，两阶段设计的效用取决于筛查与诊断评估的相对成本。
