DEVIANCE ESTIMATES OF SAMPLE-SIZE FOR EQUIVALENCE TESTS IN VACCINE TRIALS

This paper proposes a sample size procedure for both equivalence and c onventional tests for the comparison of two binomial proportions, base d on the signed square root of the deviance. When the comparison is ba sed on the odds ratio, I describe an alternate 'close' conditional exa ct method that gives results that support those given by the deviance method. I summarize the advantages of the deviance-based method and al so show that in general equivalence situations the sample size estimat e depends upon the measure of comparison selected, odds ratio, risk ra tio or risk difference.