Re: [IP] Meters Differ in readings
At 11:33 AM 7/31/03 -0400, you wrote:
>Why do all (3) of my meters (plasma) show a difference in the readings? I
>have (3) One Touch Ultra's, bought within a short time of one another. They
> read out as 150/190/210, with the same drop of blood, at the same time.
>a big difference in these numbers. I have used the solution that comes with
>the Ultras but that does not do anything.
From the archives, courtesy of Jim Handsfield, who works for the CDC
I'll put on my professional hat for this one.
Federal regulations require all waived laboratory tests, which includes
home glucose test meters, to achieve certain standards before they may be
marketed. There are two basic standards: 1) the device must be simple
enough so that the instructions may be read, understood, and followed
without assistance by someone with a seventh grade education; and 2) the
device must have results that are within 5% of a standard equivalent
laboratory test (moderate complexity) 50% of the time. That precision level
is approximated as +/- 20% of the laboratory tests (not another meter).
If you compare meters against each other, the ranges of precision have to
be compounded (IOW, the precision ranges will be quite a bit greater than
+/- 20%) to get the appropriate range because they are not independent
events. It is inappropriate for that reason to compare the results of home
test meters against each other. The only reliable test is to do your own
test at the same time you are having blood drawn for a laboratory glucose
These standards were/are developed by the Standards Branch of the Division
of Laboratory Systems of CDC where I work. I have provided statistical
support for this branch on several occasions.
If you believe your meter is not sufficiently accurate or precise, contact
the manufacturer. They generally have very liberal replacement policies.
But giving comparisons against other meter results won't suffice.
email @ redacted
The opinions expressed are mine and do not necessarily represent those of
my wife who runs our house and makes more important decisions than I do.
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