Posted by Sten Westgard, MS
More evidence of pre-analytical error rates, this time for the Journal of Clinical Pathology. This is from a study back in 2010, my apologies for only finding it this year:
A Six Sigma approach to the rate and clinical effect of registration error in a laboratory, Naadira Vanker, Johan van Wyk, Annalise E. Zemlin, Rajiv T Erasmus, J Clin Pathol 2010:63:434-437.
In this study, they reviewed 47,543 test request forms from a 3 month period of November 2008 to February 2009. The study was conducted at the "chemical pathology laboratory at Tygerberg Hospital - an academic tertiary hospital in the Western Cape Province of South Africa. The laboratory is a division of the National Health Laboratory Services, which is a network of 265 pathology laboratories in South Africa."
Can you guess how many errors they found? And what was the impact of those errors?
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Posted by Sten Westgard, MLO
In the November 2012 MLO magazine there is an intriguing article by Roy Midyett, a hematology supervisor, titled "Empty QC"
Here's how Mr. Midyett defines "Empty QC":
"Empty QC is any nominal QC that does not give techs performing the
test any more confidence than they would have without the QC, and has by
logic or experience, no influence on the reporting of the test."
Is Mr. Midyett correct? Have our QC procedures become meaningless gestures? More after the jump.
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Posted by Sten Westgard, MS
I recently got a smart question from a concerned laboratory scientist. After reviewing one of the Sigma-metric studies on the website, he noted that while a particular method had a bad Sigma-metric, the main reason was due to the bias. His question was essentially (and I am paraphrasing here), "If the bias component comes from a particular difference between the instrument or kit and a reference system, shouldn't it be excluded from the Sigma-metric calculation?"
The reasoning is that the bias problem could be (1) eliminated through recalibration, (2) it may be a bias against a method that is not a reference method, so the difference might not be "real", or (3) if the reference range is adjusted and the method is used in exclusion, bias doesn't matter anyway.
We've had a lot of discussion about bias in our statistics lately. Is this a case where the Sigma-metric is "skewed"? What's your verdict? A discussion after the jump.
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Posted by Sten Westgard, MS
During the AACC/ASCLS convention in July, we had a "live" raffle for those who attended the convention, as well as an online raffle, for those who couldn't.
Time to announce the winners...
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Posted by Sten Westgard, MS
So here's a Normalized Method Decision chart for a cholesterol method.
Which method would you choose?
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