VDSPCalibration (version 1.0)

samplesize: 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%)

Value

Required sample size to achived the specified precision in the estimated calibration equation.

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

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

# NOT RUN {
samplesize(30, 5, cutpts=c(7,42,57,72,200),0.12, 0.05)

# }