Tools, Technologies and Training for Healthcare Laboratories

The Need for a Mean Rule: Designing QC for Phosphorus

Here's a question about "Westgard Rules" that we get a LOT: "Does the violation of the 10x rule mean anything? Can we ignore it?" At the heart of this question is another, deeper question: what QC rules are actually necessary to assure the quality of a method? With the help of user-submitted data on a phosphorus method, we'll take a closer look at this question.

What's the TEa for D? Allowable Error for vitamin D

Stockl et al's landmark paper on vitamin D establishes desirable specifications for imprecision and inaccuracy (trueness). But what about total allowable error? With the use of QC Design tools, we can turn individual specifications into a broader quality requirement.

Glucose, European Biologic Goal

This example shows how to perform QC Design for a glucose method, using European biologic goals.

QC for Sysmex Hematology parameters

Based on the Sigma-analysis of the Sysmex xt 1800i, we apply QC Design and analyze the different QC procedures appropriate for different quality requirements.


A simple example planning QC for potassium using power function and critical-error graphs.