Sample size calculations for Phase 1 PK study design

This function calculates sample size based on a desired standard error of the mean, to a specified confidence, for a given mean and standard deviation.

Usage

ss.PK(n, mean, sd, precision, ci = 0.95)

Arguments

n

Sample size. This value can be missing if sample size is desired, or specified to calculate the maximum sd for given mean, precision, and `ci.

mean

Mean prameter value. User value is mandatory.

sd

Standard deviation of parameter values. If present, the function will return n. If missing and n` is specified, will return the maximum sd as detailed above.

precision

Desired width of the standard error of the mean (SEM). Default is 0.2, i.e. 20% or 10% below and 10% above the mean. If missing, and mean, sd and n are specified, precision will be calculated.

ci

Confidence for the desired width of the SEM. Default is 0.95.

Value

The missing argument: n, sd or precision.

Details

The formula is n = qnorm((1+ci)/2)**2 * sd**2 / (precision*mean)**2

Author

Michael Neely