Posted by Sten Westgard, MSAlan Greenspan gave some instantly notorious testimony to the US Congress recently:“I was right 70 percent of the time, but I was wrong 30 percent of the
time,” I'm not sure what was more concerning; the fact that he admitted that almost a third of the time he was wrong, or that he clearly believes that being right only 70% of the time was acceptable. Clearly, for a man once called "The Oracle" and Maestro, he was lowering the bar on the standards for judging him.Testimony like that raises some instant questions:
If Alan Greenspan was responsible for setting the direction of the
world's greatest economy, is a 30% error rate acceptable?
If Alan Greenspan was an airline, would you fly him?
If Alan Greenspan was a core laboratory test, would you buy the instrument?
If Alan Greenspan was a glucose meter, would you buy the device?
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Posted by Sten Westgard, MSWe've probably never met before. Maybe you're a reader of this blog. Or a visitor to the website, like the tens of thousands of laboratory professionals who visit the website every month, accessing hundreds of free articles, lessons, and examples of quality control. Or perhaps you're one of the thousands who have taken our online courses or purchased and read our many books and reference manuals. But it is highly probable that we have never talked, emailed, or had a discussion with each other.And maybe that's not good.
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Posted by Sten WestgardThis month, Dr. Westgard was teaching his spring semester class for the University of Wisconsin Medical Technology school. He likes to use recently published papers in the scientific literature as a way to relate his lessons to things happening in the "real world" of the laboratory.This semester, he has written up a number of lessons covering HbA1c methods, performance, and quality requirements based on the article in Clinical Chemistry, Few Point-of-Care Hemoglobin A1c Assay Methods Meet Clinical Needs,
by David E. Bruns1 and James C. Boyd and a study by Lenters-Westra and
Slingerland (Six out of eight hemoglobin A1c point-of care instruments do not meet the generally accepted analytical performance criteria. Clin Chem 2010;56:44 –52.)For your convenience, here are the lessons in order...
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In the January editorial of Clinical Chemistry, Few Point-of-Care Hemoglobin A1c Assay Methods Meet Clinical Needs, by David E. Bruns1 and James C. Boyd, there’s a key paragraph that goes beyond the HbA1c methods covered by the study by Lenters-Westra and Slingerland (Six out of eight hemoglobin A1c point-of care instruments do not meet the generally accepted analytical performance criteria. Clin Chem 2010;56:44 –52.)“There is increasing recognition of a need to improve the precision of HbA1c assays, in view of the low biological variability of Hb A1c. The NGSP plans to reduce theacceptability specification for level 1 laboratories to 0.70% and for manufacturers of all Hb A1c methods to <0.75% in 2010 (http://www.ngsp.org/ ngsp/prog/News/manuf09.html; accessed October 28, 2009). The College of American Pathologists (CAP) also has recognized the need to tighten total error criteria for Hb A1c and is in the process ofrevising the criteria used in grading proficiency tests (http://www.ngsp.org/ngsp/prog/News/manuf09.html; accessed October 28, 2009). In 2007,the limit specified by the CAP for acceptability on HbA1c proficiency testing was +/- 15% of the target value. This limit was lowered to +/-12% in 2008 and to +/-10% in 2009, and it will be lowered to +/-8% in 2010 and to +/-6% in 2011. “As these quality requirements tighten, how are we going to respond?
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