VarWT {dfmeta}

The variance weighted (VarWT) pooling approach.

Description

An alternative method to combine toxicities across the trials. Accordingly, we estimate the pooled toxicity probability at dose level x using the

$R_c(x) = \sum_{i=1}^{R} \frac{\sigma_{i}^2 (x)}{\sigma^{2}(x)} \bar{R_i}(x),$

where

$\sigma_{i}^2(x) = N_i(x)\bar{R_i}(x)(1-\bar{R_i}(x))$

and

$\sigma^{2}(x) = \sum_{i=1}^{R} \sigma_i^2 (x), x \in D.$

Then, to find the pooled estimates of MTD you can use either (a) the non-parametric pooled MTD estimator can be definied by the dose $x_0 \in D$ such that:

$|R_c(\hat{x_0}) - \theta| <= |R_c(x) - \theta|, x \neq \hat{x_0}$

OR (b) the model-based algorithm.

Usage

VarWT(dataTox, saveName)

Arguments

dataTox

a data frame containing information for each patient at each simulation and trial.

saveName

the name of the .txt output which will be created and saved in the current working directory; must be in characters; defaults to NULL. If saveName = NULL, means that nothing will be saved in the working directory.

Value

A list is returned, combining the toxicities across the trials. The output, generated by the function VarWT, contains the following components:

dataTox

A data frame containing the estimated pooled toxicity probabilities at each dose level for each simulation.

If saveName is not equal to "NULL" then a .txt file is saved in the working directory storing the estimated pooled toxicity probabilities at each dose level for each simulation.

Author(s)

Artemis Toumazi <[e-mail]>, Sarah Zohar <[e-mail]>, Anand N. Vidyashankar <[e-mail]>, Jie Xu <[e-mail]> and Moreno Ursino <[e-mail]>

See Also

ZKO

Examples

  ## Not run: 
    ## Using the toxicity dataset for each simulation and each trial, which is 
    ## existing in the dfmeta package.
    
    data("Toxdata")
    dim(Toxdata)
    colnames(Toxdata)
    
    ## NOTE: The toxicity dataset must have the same structure as below. ##
    ## Check it before running the VarWT function! ##
    
    str(Toxdata)

    #################################
    ## Running the VarWT function! ##
    #################################
    
    WT <- VarWT(Toxdata)
    
    ######### If we want to save the result in a text file ###########
    ####### we need to give a name in the argument "saveName" ########
    
    WT <- VarWT(Toxdata, tempdir())
  
## End(Not run)