PwrSampleSize {SynergyLMM}R Documentation

A Priori Synergy Power Analysis Based on Sample Size

Description

A priori power calculation for a hypothetical two-drugs combination study of synergy evaluation using linear-mixed models depending on the sample size per group.

Usage

PwrSampleSize(
  npg = c(5, 8, 10),
  time = c(0, 3, 5, 10),
  grwrControl = 0.08,
  grwrA = 0.07,
  grwrB = 0.06,
  grwrComb = 0.03,
  sd_ranef = 0.01,
  sgma = 0.1,
  method = "Bliss",
  ...
)

Arguments

npg

A vector with the sample size (number of subjects) per group to calculate the power of the synergy analysis.

time

Vector with the times at which the tumor volume measurements have been performed.

grwrControl

Coefficient for Control treatment group tumor growth rate.

grwrA

Coefficient for Drug A treatment group tumor growth rate.

grwrB

Coefficient for Drug B treatment group tumor growth rate.

grwrComb

Coefficient for Combination (Drug A + Drug B) treatment group tumor growth rate.

sd_ranef

Random effects standard deviation for the model.

sgma

Residuals standard deviation for the model.

method

String indicating the method for synergy calculation. Possible methods are "Bliss" and "HSA", corresponding to Bliss and highest single agent, respectively.

...

Additional parameters to be passed to nlmeU::Pwr.lme method.

Details

PwrSampleSize allows the user to define an hypothetical drug combination study, customizing several experimental parameters, such as the sample size, time of measurements, or drug effect, for the power evaluation of synergy for Bliss and HSA reference models. The power calculation is based on F-tests of the fixed effects of the model as previously described (Helms, R. W. (1992), Verbeke and Molenberghs (2009), Gałecki and Burzykowski (2013)).

The focus the power analysis with PwrSampleSize is on the sample size per group. The function allows for the evaluation of how the statistical power changes when the sample size per group varies while the other parameters are kept constant. For other a priori power analysis see also APrioriPwr() and PwrTime().

Value

The functions returns two plots:

The function also returns the data frame with the power for the analysis for each sample size specified in npg.

References

See Also

PostHocPwr, APrioriPwr(), PwrTime().

Examples

PwrSampleSize(npg = 1:20)


[Package SynergyLMM version 1.0.1 Index]