The permissible limits for intermediate precision in control charts


Authors: J. Ambrožová
Authors‘ workplace: Oddělení klinické biochemie Nemocnice Prachatice, a. s.
Published in: Klin. Biochem. Metab., 23 (44), 2015, No. 3, p. 109-115

Overview

Objective:
Presentation an advanced method for deriving correct permissible precision limits which are required for the correct use of control charts, and for the effective internal quality control management (IQC) in a laboratory practice.

Method:
The 3-signal table application designed by Haeckel and Wosniok [1], which provides appropriate means to calculate the correct permissible precision limits (pCVA) from the empirical biological variability (CVE), based on reference intervals (RIs); the subsequent proper use of pCVA in the control charts.

Discussion:
Potential uses of the 3-signal table [1].

Conclusion:
Warning against an improper use of the control charts; the correct method for deriving the permissible intermediate precision limits as the key ingredient for setting up effective control charts, which are a prerequisite for an objective classification of different laboratory methods according to their real quality.

Keywords:
permissible precision limits, quality classes, reference limits, control charts.


Sources

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