ThreeArmedTrials (version 1.0-4)

opt_alloc_RET: Optimal sample size for three-arm trials when analyzed with a Wald-type test

Description

Calculate optimal sample size allocation for Wald-type test for superiority or non-inferiority of the experimental treatment versus reference treatment with respect to placebo

Usage

opt_alloc_RET(experiment, reference, placebo, Delta, distribution, h = NULL)

Value

Vector with optimal sample size allocation in the order (experiment, reference, placebo)

Arguments

experiment

a numeric vector specifying the parameters of the experimental treatment group in the alternative hypothesis

reference

a numeric vector specifying the parameters of the reference treatment group in the alternative hypothesis

placebo

a numeric vector specifying the parameters of the placebo treatment group in the alternative hypothesis

Delta

a numeric value specifying the non-inferiority/superiority margin

distribution

a character specifying the distribution of the endpoints. Must must be either of "poisson", "negbin", "exponential", "normal"

h

Function measuring the efficacy; used to defined hypothesis

Details

The arguments experiment, reference, and placebo define the parameters of the endpoint distribution for the respective groups:
distribution = "poisson": experiment, reference, and placebo must have length one and define the means.
distribution = "negbin": experiment, reference, and placebo must have length two and define the mean in the first entry and the shape parameter in the second entry.
distribution = "exponential": experiment, reference, and placebo must have length two and define the mean in the first entry and the probability for an uncensored observation in the second entry.
distribution = "normal": experiment, reference, and placebo must have length two and define the mean in the first entry and the variance in the second entry.

Examples

opt_alloc_RET(experiment = 1,
              reference = 1,
              placebo = 3,
              Delta = 0.8,
              distribution = "poisson")