Sample Size Estimation when Comparing More than Two Treatment Groups

  • Alan PhillipsEmail author


A large amount of literature has been published on methods for determining sample size and power for clinical trials. Although formulae exist to determine sample size for different designs, in practice the methods are rarely used. Instead, sample size estimates are usually based on simple formulae derived for the comparison of two means or binomial proportions.

This paper describes some useful theory for sample size estimation when comparing more than two treatment groups. Where the theory is not applicable, it is demonstrated that simulation can be used as an alternative approach.

Key Words

Sample size Analysis of variance Dose-response Simulation 


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Copyright information

© Drug Information Association, Inc 1998

Authors and Affiliations

  1. 1.Huntercombe Lane South, TaplowWyeth Research (UK)BerkshireUK

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