| dabcd_min_var {RARtrials} | R Documentation |
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 ((Hu and Zhang 2004)), 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 ((Hu and Zhang 2004)). When |
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 (Hu and Zhang 2004).
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
Hu F, Zhang L (2004). “Asymptotic Properties of Doubly Adaptive Biased Coin Designs for Multitreatment Clinical Trials.” The Annals of Statistics, 32(1), 268–301.
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')