Tools, Technologies and Training for Healthcare Laboratories

Update on Measurement Uncertainty: CLSI C51A

Uncertainty is an ISO-driven metrological concept. For years, while it has been popular in Europe, uncertainty has been discussed in the US, but never implemented. Now that CLSI has issued its C51A guideline, uncertainty is now official in the US, too. The C51 guideline is worth exploring in detail, for those who seek metrological orthodoxy in their testing processes.


W.o.W, part III: Intended Applications and Customers

October 2007

Looking beyond the terminology of Trueness and Uncertainty, Dr. Westgard examines the intended uses and customers of these terms. If we spend our time fighting about Metrological definitions, are we serving the patient?

W.o.W., part II: Concepts and Terminology

October 2007

Trueness. Uncertainty. Accuracy. Precision. Why are there so many definitions for the same terms? Dr. Westgard traces the history of metric concepts in the clinical laboratory. See when and where ISO, IFCC, and CLSI began introducing new terminology into the lab.

W.o.W., part I: Total Error vs. Trueness and Measurement Uncertainty

September 2007

Total Error. Trueness. Uncertainty. Can these terms coexist? Under ISO, will defining an allowable error for a test become unacceptable? Will the embrace of ISO accreditation mandate the rejection of all non-ISO-conforming terminology and concepts?

The debate - and the future - is uncertain.

Truthful Guidance about Trueness, Uncertainty and Quality

February 2007

We need some truthful guidance about Trueness, Uncertainty and Quality. This year's regulations feature new terminology that adheres to ISO conventions. As we leave behind our familiar concepts of precision, bias, and total error, are we gaining anything? Are we just changing names, or are we changing our goals, too?