The development of group sequential methods has produced multiple criteria that are used to guide the decision of whether a clinical trial should be stopped early given the data observed at the time of an interim analysis. However, the potential for time-varying treatment effects should be...

Transitivity is an important property of any statistic applied in the setting of multi-arm clinical trials and non-inferiority trials where active-controls are used. The G[rho],[gamma] class of weighted logrank statistics for right-censored survival data as proposed by Fleming and Harrington...