"Efficient Alternatives to the Mantel-Haenszel and van Elteren Tests for Stratified Trials"
November 11, 2008 @ 3:30 pm - 4:30 pm
Devan Mehrotra, Merck Research Labs.
Location: John Morgan Building Reunion Hall
TITLE: Efficient Alternatives to the Mantel-Haenszel and van Elteren Tests for Stratified Trials
The Mantel-Haenszel test (for binary data) and the van Elteren test (for ranked data), are two popular methods for the analysis of stratified trials. In this two-part talk, I will show that these "standard" methods have good power properties only under restrictive assumptions that, unfortunately, are commonly violated in practice. In part I, I will review and illustrate the notable power gains of a "minimum risk" alternative to the MH procedure (and to MH-like procedures) for both superiority and non-inferiority trials. Likewise, in part II, I will contrast published and new alternatives to the van Elteren test. Using extensive simulations, two alternate rank-based procedures will be shown to be substantially more powerful than the van Elteren test. Throughout the presentation, numerical examples will be used to illustrate the methods, and to reinforce the key points.