stage_1_selection {GSED}

Stage 1-selection step of GSED

Description

stage_1_selection is used to determine the subgroup selected at the end of the first stage of GSED.

Usage

stage_1_selection(N_subsets, Z_1j, l, ordering, increasing_theta=FALSE)

Arguments

N_subsets

Integer representing the number of possible subgroups.

Z_1j

Vector containing the Z-statistics (standard normal under H0) for each subgroup. Must be of length N_subsets.

l

Vector containing the lower boundaries for stagewise decisions.

ordering

Boolean indicating if the subgroups (theta) are ordered.

increasing_theta

Boolean indicating if greater values of theta parameters represent better treatment effects. The default value is set at FALSE.

Value

A vector containing the indices of the subgroups selected is returned.

Author(s)

Marie-Karelle Riviere-Jourdan [e-mail]

References

Baldur P. Magnusson and Bruce W. Turnbull. Group sequential enrichment design incorporating subgroup selection. Statistics in Medicine, 2013. <doi:10.1002/sim.5738>

Examples

stage_1_selection(N_subsets=3, Z_1j=c(-0.49,1.07,1.44), l=c(0.7962,2.5204), ordering=FALSE)