dabcd_min_var: Allocation Probabilities Using Doubly Adaptive Biased Coin...

In RARtrials: Response-Adaptive Randomization in Clinical Trials

Allocation Probabilities Using Doubly Adaptive Biased Coin Design with Minimal Variance Strategy for Binary Endpoint

Description

dabcd_min_var can be used for doubly adaptive biased coin design with minimal variance strategy for binary outcomes, targeting generalized Neyman allocation and generalized RSIHR allocation. The return of this function is a vector of allocation probabilities to each arm, with the pre-specified number of participants in the trial.

Usage

dabcd_min_var(NN, Ntotal1, armn, type, dabcd = FALSE, gamma = 2)

Arguments

NN	a vector representing the number of participants with success results for each arm estimated from the current data .
Ntotal1	a vector representing the total number of participants for each arm estimated from the current data.
armn	number of total arms in the trial.
type	allocation type, with choices from 'RSIHR' and 'Neyman'.
dabcd	an indicator of whether to apply Hu & Zhang's formula (\insertCiteHu2004RARtrials), with choices from FALSE and TRUE. TRUE represents allocation probabilities calculated using Hu & Zhang's formula; FALSE represents allocation probabilities calculated before applying Hu & Zhang's formula. Default value is set to FALSE.
gamma	tuning parameter in Hu & Zhang's formula (\insertCiteHu2004RARtrials). When dabcd=FALSE, this parameter does not need to be specified. Default value is set to 2.

Details

The function simulates allocation probabilities for doubly adaptive biased coin design with minimal variance strategy targeting generalized Neyman allocation and generalized RSIHR allocation with 2-5 arms. The output of this function is based on Hu \& Zhang's formula \insertCiteHu2004RARtrials. With more than two armd the one-sided nominal level of each test is alphaa divided by arm*(arm-1)/2; a Bonferroni correction.

Value

A vector of allocation probabilities to each arm.

Author(s)

Chuyao Xu, Thomas Lumley, Alain Vandal

References

\insertRef

Hu2004RARtrials

Examples

dabcd_min_var(NN=c(54,67,85,63,70),Ntotal1=c(100,88,90,94,102),armn=5, type='Neyman')
dabcd_min_var(NN=c(54,67,85,63),Ntotal1=c(100,88,90,94),armn=4,type='RSIHR')

RARtrials documentation built on April 4, 2025, 1:21 a.m.