A Note on Comparing Two Binomial Proportions in Confirmatory Noninferiority Trials

We evaluate the performance of two commonly used methods to construct confidence intervals for noninferiority decisions when the primary end point is binary. The two methods are the classical asymptotic normal approximation procedure and the same procedure with the Hauck-Anderson type of continuity correction. Simulations were conducted to explore the rate of erroneously concluding noninferiority when the new treatment is worse than the active control by the amount defined by the noninferiority margin. The evaluation was conducted with sample sizes relevant to the confirmatory trials. Based on the findings from the simulations, we provide some practical guidance to individuals responsible for the analysis of such trial data.