TESTING STRATEGIES IN MULTIDOSE EXPERIMENTS INCLUDING ACTIVE CONTROL

Inferential test strategies for multi-arm trials are adapted or propos ed for the special situation when more than one dose of a test treatme nt, placebo and active control(s) are compared. This includes between doses, dose-placebo and dose-active-control comparisons. The procedure s refer to situations when detailed comparisons make sense only if the sensitivity of the trial has been shown, for example, if a dose-respo nse relationship or a difference between active control and placebo ha s been established. Split strategies, hierarchical (assuming an order restriction among doses) or linked procedures are introduced. In linke d procedures, equivalence to the active control will be established on ly if the dose is also shown to be effective as compared to placebo. A ll the inferential procedures control the experimentwise error rate in the strong sense for the respective sets of null hypotheses considere d. (C) 1998 John Wiley & Sons, Ltd.