SAMPLE-SIZE FOR REPEATED-MEASURES STUDIES WITH BINARY RESPONSES

We consider the sample size required for repeated measures studies whe n the response variable is binary. We propose the use of weighted leas t squares (WLS) for calculating the minimum sample size required to de tect some minimum clinically important treatment effect. We provide ta bulated values of the estimated sample sizes for a simple example and we discuss some practical considerations in determination of sample si ze with repeated binary responses.