Binomial Endpoint: Exact Distribution Q. Is East 4 group sequential design and analysis for Binomial endpoint based on exact binomial distribution?
A. No. At present, East does not have an exact group sequential test for the two-binomial problem. However, we do have a simulation module that allows you to simulate from a binomial population and verify that the operating characteristics provided by East are valid. Our experience with this module shows that for sample sizes of 100 or more the asymptotic theory works out very accurately (unless the treatment arms are severely unbalanced).