Prof. Chengjie Xiong
Division of Biostatistics, School of Medicine
Washington University at St. Louis

Title:
Discriminant Analyses in Biomedical Studies

Abstract:
     The discriminant analyses in biomedical research are in general associated with discriminating diseased individuals from normal healthy individuals through estimating the diagnostic accuracy. The diagnostic accuracy of a given diagnostic test has been traditionally measured by sensitivity and specificity, as well as the area associated with the Receiver Operating Characteristic (ROC) curve. In this talk, we will first discuss several extensions to the statistical estimation/comparison of diagnostic accuracy based on ROC curves with different types of diagnostic tests. We will then discuss the problem of measuring/estimating/comparing diagnostic accuracy when more than two diagnostic alternatives are available. Finally, we will present an application of the ROC curve/surface-based statistical methodologies to search for a subset of genes whose microarray expression profiles provide (in certain sense) the optimum discriminatory power between two sources of RNA.