GroupSeq

An R package providing a GUI-Based Tool to Compute Probabilities of Group Sequential Designs.

Allows to compute group sequential designs based on normally distributed test statistics, particularly critical boundaries, power, drift, and confidence intervals of such designs. All computations are based on the alpha spending approach by Lan-DeMets with various alpha spending functions being available to choose among.

Available on CRAN: https://CRAN.R-project.org/package=GroupSeq