post_power {bpp}

Conditional power conditioning on a blinded interim

Description

Conditional power conditioning on a blinded interim, i.e. the estimate after the interim is only known to lie in an interval.

Usage

post_power(x, interimSE, finalSE, successmean, IntEffBoundary, IntFutBoundary)

Arguments

x

Value at which to evaluate the function.

interimSE

(Known) standard error of interimmean.

finalSE

(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.

Author(s)

Kaspar Rufibach (maintainer)
[e-mail]

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.

Examples

# type ?bpp_1interim for code of all the computations in Rufibach et al (2016a).