Calculate Refined Secondary Boundary, Error Spending Approach
Refined secondary boundaries are calculated by using the error spending approach.
ldSecondaryBoundary(alpha, tVec, cvec, locPeak, type = 2, initIntvl = c(0.6, 4))
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. |
This function calculates the refined secondary boundaries of any Lan-DeMets error spending boundary based on the primary boundaries.
refined secondary boundaries.
Jiangtao Gou
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.
secondaryBoundary, secondaryBoundaryVecLD
#require(mvtnorm) #require(ldbounds) #K <- 6; #tVec <- c(140,328,453,578,659,1080)/1080; #alpha = 0.025; #cvec.obf <- bounds(tVec,iuse=c(1),alpha=c(alpha)); #cvec <- cvec.obf$upper.bounds; #secbound <- ldSecondaryBoundary(alpha,tVec,cvec,locPeak=4,type=2, # initIntvl=c(0.8,8))
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