| samplesize {VDSPCalibration} | R Documentation |
Uniform Sampling Within Quartiles
Description
Estimates the sample size to achived the specified precision in the estimated calibration equation.
Usage
samplesize(x0, d0, cutpts = c(7.5, 42.5, 57.5, 72.5, 200), CVx, CVy)
Arguments
x0 |
The value at which calibration will be esitmated (e.g., 30 nmol/L) |
d0 |
Targeted width of the 95% confidence interval of the calibrated value (e.g. 5nmol/L) |
cutpts |
Cut points used to define intervals, within which samples would be selected uniformly |
CVx |
CV% of the old method (e.g. 12%) |
CVy |
CV% of the reference (new) method (e.g. 5%) |
Details
The function estimates the sample size to achived the specified precision in the estimated calibration equation. The precision is defined via x0 and d0
Value
Required sample size to achived the specified precision in the estimated calibration equation.
Author(s)
Durazo-Arvizu, Ramon, Sempos, Chris and Tian, Lu
References
Tian L., Durazo-Arvizu R. A., Myers G., Brooks S., Sarafin K., and Sempos C. T. (2014), The estimation of calibration equations for variables with heteroscedastic measurement errors, Statist. Med., 33, pages 4420-4436
Examples
samplesize(30, 5, cutpts=c(7,42,57,72,200),0.12, 0.05)