RPWRule {grouprar}

Randomized Play-the-winner Rule

Description

Simulating randomized play-the-winner rule with two-sided hypothesis testing in a clinical trial context.

Usage

RPWRule(k, p, ssn, Y0 = NULL, nsim = 2000, alpha = 0.05)

Arguments

k

a positive integer. The value specifies the number of treatment groups involved in a clinical trial. (k = 2)

p

a positive vector of length equals to k. The values specify the true success rates for the various treatments, and these rates are used to generate data for simulations.

ssn

a positive integer. The value specifies the total number of participants involved in each round of the simulation.

Y0

A vector of length k, specifying the initial probability of allocating a patient to each group. For instance, if Y0 = c(1, 1,), the initial probabilities are calculated as Y0 / sum(Y0). When Y0 is NULL, the initial urn will be set as If Y0 is NULL, then Y0 is set to a vector of length k, with all values equal to 1 by default.

nsim

a positive integer. The value specifies the total number of simulations, with a default value of 2000.

alpha

An integer between 0 and 1. The value represents the predetermined level of significance that defines the probability threshold for rejecting the null hypothesis, with a default value of 0.05.

Details

The Randomized Play-the-Winner Rule allocates future subjects in a clinical trial to treatment groups based on the performance of previously treated subjects. This rule increases the likelihood of future patients being assigned to the better-performing treatment, as determined by the outcomes of previously treated subjects.

Value

name

The name of procedure.

parameter

The true parameters used to do the simulations.

assignment

The randomization sequence.

propotion

Average allocation porpotion for each of treatment groups.

failRate

The proportion of individuals who do not achieve the expected outcome in each simulation, on average.

pwClac

The probability of the study to detect a significant difference or effect if it truly exists.

k

Number of arms involved in the trial.

References

L. J. WEI and S. DURHAM (1978) The Randomized Play-the-Winner Rule in Medical Trials. Journal of the American Statistical Association, 73, 364, 840–843.

Examples

## a simple use
RPW.res = RPWRule(k = 2, p = c(0.7, 0.8), ssn = 400, Y0 = NULL, nsim = 200, alpha = 0.05)
## view the output
RPW.res


  ## view all simulation settings
  RPW.res$name
  RPW.res$parameter
  RPW.res$k

  ## View the simulations results
  RPW.res$propotion
  RPW.res$failRate
  RPW.res$pwCalc
  RPW.res$assignment