Compare more than two treatment under a crossover design.
H0: margin \( \le \delta \) Ha: margin > \(\delta\)
if \(\delta\) >0, the rejection of Null Hypothesis indicates the superiority of the test over the control;
if \(\delta\) <0, the rejection of the null hypothesis implies the non-inferiority of the test against the control.
MeanWilliamsDesign.NIS(alpha, beta, sigma, k, delta, margin)significance level
power = 1-beta
standard deviation
Total k treatments in the design
the superiority or non-inferiority margin
\(margin=\mu_i-\mu_j\) the difference between the true mean response of group i \(\mu_i\) and group j \(\mu_j\)
Chow SC, Shao J, Wang H. Sample Size Calculation in Clinical Research. New York: Marcel Dekker, 2003