(Known) standard error at which the final analysis of the study under consideration takes place.
successmean
The mean that defines success at the final analysis. Typically chosen to be the minimal detectable difference, i.e. the critical on the scale of the effect size of interest corresponding to the significance level at the final analysis.
IntEffBoundary
Efficacy boundary at the interim analysis.
IntFutBoundary
Futility boundary at the interim analysis.
Value
Value of the function, a real number.
References
Rufibach, K., Jordan, P., Abt, M. (2016a).
Sequentially Updating the Likelihood of Success of a Phase 3 Pivotal Time-to-Event Trial based on Interim Analyses or External Information.
J. Biopharm. Stat., 26(2), 191--201.