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RE: [IP] Quick questions - need answer before Sat morning

Eloisa [mailto:email @ redacted] wrote:

>  I know this may sound stupid, but how exactly does one do to 
> check a meters
> accuracy when taking blood from my vein?

Bottom line is that you don't.  The only way to check the meter is with the
check solution.  You might get an approximation by testing your own blood at
the same time it is drawn for a fasting glucose - which probably wouldn't be
done unless you specifically ask (and pay) for it.  

And if you do get a fasting glucose to compare with your meter, there are
several variables that have to be taken into account.  First, make sure you
are reading the same units.  Many meters display results as blood glucose.
The lab will spin out the RBCs before doing the test, so it will be a serum
glucose.  All meters measure blood glucose, but those that report a serum
glucose do so by applying an algorithm to convert.  This is necessarily an
approximation which depends on hematocrit, red cell volume, white cell
volume, platelet volume, etc.

Home test meters are considered under the Clinical Laboratory Improvement
Amendments of 1988 (CLIA88) as waived lab tests.  All waived test meet the
same criteria: the device must be operable without special training by
someone with a 7th grade education; the results must be within 5% of a
standard lab test 50% of the time.  This last is approximated (another
approximation!) as +/- 20%.

Home meters work well when we use them to control our blood glucose and to
see trends in that control.  They are not intended for anything more than
that, and it really isn't helpful to try to compare them with standard lab
tests (the criteria mentioned earlier is a burden on the manufacturer).

Because of the nature of this post, I'm using my work sig.  

James Handsfield, PhD, MPH
Division of Laboratory Systems
Public Health Practice Program Office
Centers for Disease Control and Prevention
email @ redacted
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