A simulation study of the Westgard multi-rule quality-control system for clinical laboratories.

A particular version of the Westgard-Barry-Hunt-Groth (Westgard) multi-rule quality-control system is studied by Monte Carlo simulation. The principal focus is on the amount of distortion in the working power curve caused by skewness in the distribution of analyte measurements. The effect of using only the first two rejection modes of the Westgard system is also studied.