SSR.boundary {esDesign}

Calculate the futility and efficacy stopping boundaries for Sample Size Re-estimation Procedure based on the conditional error function

Description

The SSD.boundary() is used to calculate the futility and efficacy stopping boundaries, meanwhile protect the overall Type I error rate at the pre-specified level.

Usage

SSR.boundary(alpha, pstar)

Arguments

alpha

The overall Type I error rate

pstar

The (1 - power) of accepting the null hypothesis at the interim analysis.

Value

A list contain

• upper.boundary The efficacy stopping boundary at the interim analysis

• lower.boundary The futility stopping boundary at the interim analysis

References

• Proschan MA, Hunsberger SA. Designed extension of studies based on conditional power. Biometrics 1995:1315-24. <doi:10.2307/2533262>

Examples

alpha <- 0.05
pstar <- 0.2
res <- SSR.boundary(alpha = alpha, pstar = pstar)