Journal alert: Sigma-metrics in CCLM

Posted by Sten Westgard, MS

Clinical Chemistry and Laboratory Medicine just published an article where I am a co-author:

Sigma metrics used to assess analytical quality of clinical chemistry assays: importance of the allowable total error (TEa) target. Koen Hens, Mario Berth, Dave Armbruster, Sten Westgard. CCLM. Volume 12, Issue 7, 973-980.

We looked at three high volume chemistry analyzers in the AML reference laboratory in Belgium, and calculated Sigma-metrics for 25 basic chemistry tests at 2 different levels, and further assessed them using three different sources for allowable total error: the CLIA specifications, the German Rilibak rules, and the biologic variation desirable specifications ("Ricos goals"). For those who like tables and data, this study has a lot of it. That's 450 different Sigma-metrics we calculated.

The biggest finding was how different the different sources of allowable total errors are. Choosing the right target is critical in determining your Sigma-metric.

Some of this data will also be presented at the IFCC conference in Istanbul next week.