groupSampleSize {ASSISTant}

Compute the sample size for any group at a stage assuming a nested structure as in the paper.

Description

In the three stage design under consideration, the groups are nested with assumed prevalences and fixed total sample size at each stage. This function returns the sample size for a specified group at a given stage, where the futility stage for the overall group test may be specified along with the chosen subgroup.

Usage

groupSampleSize(
  prevalence,
  N,
  stage,
  group,
  HJFutileAtStage = NA,
  chosenGroup = NA
)

Arguments

prevalence

the vector of prevalence, will be normalized if not already so. The length of this vector implicitly indicates the number of groups J.

N

an integer vector of length 3 indicating total sample size at each of the three stages

stage

the stage of the trial

group

the group whose sample size is desired

HJFutileAtStage

is the stage at which overall futility occured. Default NA indicating it did not occur. Also ignored if stage is 1.

chosenGroup

the selected group if HJFutilityAtStage is not NA. Ignored if stage is 1.

Value

the sample size for group