GSD_allocation function

Calculates the Type I error for different randomization sequences from a randomization procedure for a group sequential design

GSD_allocation(
  n,
  reps,
  sfu,
  K,
  rp,
  seed = 42,
  ui = "No",
  rb = 4,
  mti = 3,
  p = 2/3
)

Arguments

• n: total sample size
• reps: number of simulations to be conducted
• sfu: Group sequential design used (currently available: "Pocock" - Pocock, "OF" - O'Brien & Fleming, sfLDPocock - Lan & DeMets with Pocock like alpha spending function, sfLDOF - Lan & DeMets with O'Brien & Fleming like alpha spending function)
• K: number of stages
• rp: the randomization procedure used (currently available: '"CR"', '"RAR"', '"BSD"', '"CHEN"', '"PBR"', '"MP"')
• seed: Randomization seed
• ui: for Lan & DeMets design. Update critical values after each stage according to allocation ratio observed if set to "yes".
• rb: Block size for randomization procedure PBR.
• mti: Maximum tolerated imbalance for randomization procedure BSD and MP.
• p: Probability p in favor of the treatment with fewer allocations for EBC and CHEN.

Returns

A list consisting of a vector of Type I errors for each randomization sequence generated from the randomization procedure and a S4 object of the class of the randomization procedure.

Examples

#Simulate a group sequential design according to O'Brien and Fleming's design with 24 patients,
#10 simulation runs,3 Stages using Random Allocation Rule as a randomization procedure.
GSD_allocation(n=24, reps=10, sfu="OF", K=3, rp="RAR")
#Simulate a group sequential design according to Lan and deMets design with a Pocock
#like alpha spending function with 18 patients, 10 simulation runs,
#3 Stages using Permuted Block Randomization with block size 4
#as a randomization procedure without updating the critical values after each stage.
library(gsDesign)
GSD_allocation(n=18, reps=10, sfu=sfLDPocock, K=3, rp="PBR", ui="no", rb=4)