SEQPWR and SEQOPR: computer programs for design of maximum information trials based on group sequential logrank tests.

The maximum information trial paradigm for clinical trials with failure time data was recognized and has been investigated. With the maximum information trial paradigm, a study is concluded when a prespecified maximum number of events of interest, thus maximum information, has been accrued if there was no early stopping due to treatment difference or lack thereof. We present two interactive FORTRAN programs for use in designing maximum information trials based on group sequential logrank tests. The program SEQPWR computes the attainable power of group sequential logrank tests given the combinations of the accrual and follow-up durations. The program SEQOPR allows the users to investigate the operating characteristics of the maximum information trial given the information fractions of interim analyses. A clinical trial from the Eastern Cooperative Oncology Group is provided to illustrate the usage and features of the programs.