There are two groups: control and experimental, mean difference is 10% between experimental group and control group [if there are X successes in control group then there are 1.1 * X successes in experimental group], significance level is 0.05, power (sensitivity = (1 - beta)) is 0.8. The number of patients in groups are equal. Which is the minimum number of patients in group?
The known formulas for sample size include standard deviation (which is unknown in this case), so we can't apply computations directly. Can we estimate the SD with the "minimum number of patients" condition? Or we need to choose other way?