A Nonparametric Multivariate Test for Monotone Trend with Pharmaceutical Applications

Abstract

During a drug trial, each subject may have many blood constituents measured at regular time intervals. The traditional method of evaluating such data using normal ranges has undergone much controversy in the clinical chemistry literature. We propose a new multivariate test for monotone trend based on Kendall's τ statistic as a way to test for change in blood constituents over the course of a drug experiment. The new test avoids the unrealistic assumptions and repeated testing problem of the normal range method. An example illustrates the new procedure.