gbounds: Critical boundary in group sequential trials

In triggerstrategy: Trigger Strategy in Clinical Trials

Critical boundary in group sequential trials

Description

This function computes the critical boundaries and the error spent until each stage in group sequential trials

Usage

gbounds(t, iuse = 1, alpha = 0.05, phi = rep(1, length(alpha)))

Arguments

t	a vector of information times
iuse	a number of the type of the error spending function, from -2, -1, 1, 2, 3, 4
alpha	a number of type I error rate
phi	a parameter for the power family or the HSD gamma family

Details

If the original Pocock is implemented, we specify iuse=-2. If the original OBrien-Flemming is implemented, we specify iuse=-1.

Value

a list of two vectors: bd critical boundaries, er error spent until each stage

Author(s)

Jiangtao Gou

Examples

t<-c(0.5,0.8,1)
iuse <- 4
gbounds(t=t, iuse=iuse)
gbounds(t=(1:5)/5, iuse=4, alpha=0.01, phi=-4)
gbounds(t=(1:5)/5, iuse=-2, alpha=0.01)

triggerstrategy documentation built on July 9, 2023, 5:25 p.m.