ldSecondaryBoundary {gsrsb}

Calculate Refined Secondary Boundary, Error Spending Approach

Description

Refined secondary boundaries are calculated by using the error spending approach.

Usage

ldSecondaryBoundary(
  alpha,
  tVec,
  cvec,
  locPeak,
  type = 2,
  initIntvl = c(0.6, 4)
)

Arguments

alpha

original significance level.

tVec

information vector.

cvec

primary group sequential boundary.

locPeak

location of maximum, a number between 1 and the number of interims.

type

type of the test procedure for the secondary endpoint. O'Brien- Fleming (OBF) type error spending funciton is 1, Pocock (POC) type error spending funciton is 2.

initIntvl

computing paramter, a pair of numbers containing the end-points of the interval to be searched for the root.

Details

This function calculates the refined secondary boundaries of any Lan-DeMets error spending boundary based on the primary boundaries.

Value

refined secondary boundaries.

Author(s)

Jiangtao Gou

References

Lan, K. K. G., and Demets, D. L. (1983). Discrete sequential boundaries for clinical trials. Biometrika 70, 659-663.

Tamhane, A. C., Gou, J., Jennison, C., Mehta, C. R., and Curto, T. (2017+). A gatekeeping procedure to test a primary and a secondary endpoint in a group sequential design with multiple interim looks. Biometrics, 74, 40-48.

See Also

secondaryBoundary, secondaryBoundaryVecLD

Examples

## Not run: 
require(mvtnorm)
require(ldbounds)
K <- 6;
tVec <- c(140,328,453,578,659,1080)/1080;
alpha = 0.025;
cvec.obf <- ldbounds::ldBounds(t=tVec,iuse=c(1),alpha=c(alpha),sides = 1);
cvec <- cvec.obf$upper.bounds;
secbound <- ldSecondaryBoundary(alpha,tVec,cvec,locPeak=4,type=2,
    initIntvl=c(0.8,8))

## End(Not run)