Sigma Metric Analysis
At a recent veterinary laboratory conference, we had the chance to review some instrument evaluations. As it happens, these evaluations are based on QC and EQA data which applies to test performance relevant to human testing as well as veterinary testing.
IFCC EFLM have recommended that HbA1c methods be assessed using Sigma-metrics. We're starting to see papers now that incorporate Sigma-metrics into the instrument assessment. What are they telling us about today's latest HbA1c instruments? Are they good enough for use with patients?
At the end of December 2016, the Turkish Clinical Biochemistry journal published a study looking at the month to month Sigma-metrics of an AU 5800. Are Sigma-metrics changing month to month on this analyzer? What does that mean for QC?
What happens when a hospital has multiple analyzers, "closed systems", "open systems" and "mixed systems"? When we use different analyzers, reagents, and calibrators, can we assume the results will always be comparable? NO. No, we can not.
In 2016, Clinical Biochemistry published a study evaluating the Sigma-metrics of the Beckman Coulter Olympus AU 680 using biological variation goals.