Sample size for a paired-samples mean superiority or noninferiority test

Computes the sample size required to perform a superiority or noninferiority test for the difference in population means with desired power in a paired-samples design. For a superiority test, specify the upper limit (h) for the range of practical equivalence and specify an effect size (es) such that es > h. For a noninferiority test, specify the lower limit (-h) for the range of practical equivalence and specify an effect size such that es > -h. Set the Pearson correlation planning value to the smallest value within a plausible range, and set the variance planning value to the largest value within a plausible range for a conservatively large sample size.

Usage

size.supinf.mean.ps(alpha, pow, var, es, cor, h)

Arguments

alpha: alpha level for hypothesis test
pow: desired power
var: planning value of average variance of the two measurements
es: planning value of mean difference
cor: planning value of the correlation between measurements
h: upper or lower limit for range of practical equivalence

Value

Returns the required sample size

Examples

size.supinf.mean.ps(.05, .80, 225, 9, .75, 4)
#>  Sample size
#>           38

# Should return:
# Sample size
#          38