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Re: [IP] old test strips


You've just pointed out the dangers of comparing meter-to-meter.

There are several factors to keep in mind.  First, of course, is the
expiration date on the test strips.  DO NOT use strips after their
expiration date.  There is absolutely NO guarantee as to their efficacy.

Second, how is the meter referenced?  If your old meter is referenced to
whole blood and the new meter is referenced to serum/plasma, there will
be an inherent 12% difference.

Third, each manufacturer has a range in which the meter is considered

Let's assume the following scenario:  Your strips are expired.  Your old
meter is whole-blood referenced.  Your new meter is serum/plasma
referenced.  Your old meter is testing at the low end of the acceptable
range.  Your new meter is reading at the high end of the acceptable

In this scenario, both meters could actually be accurate, but when
compared to each other, they look woeful.

Again using the above scenario,  let's assume that your blood sugar is
at 150 (whole blood referenced).  An acceptable range for that meter
would be 120 to 180.  So, your reading of 125 would be in the range
considered accurate.  Your serum/plasma glucose was 175.  An acceptable
range for your new meter would then be 140 to 210.  Therefore, your
reading of 205 would be considered accurate. An acceptable range, by the
way is considered to be +/- 20%.

Assuming that your blood sugar was 175 serum/plasma, your whole blood
value would be 154 (accounting for the 12% difference between serum and
whole blood.

See the problem?

Mike Maturen

Nancy Ludwig wrote:
> Hello,
> I only have 5 of some of my new meters test strips.  So I went to use my old meter and noticed that the strips Expired in April 1998.   My sugar was 125.  So I wondered how correct this was.  So I tested with my new meter and I was 205.
> Then I tested again with the old and came up with 135.  So which is right? I don't care to spend the money on more tests strips, since our insurance changes on March First.
> Any ideas?  I guess for accuarracy and health I would spend the money for new ones, but if I don't have to I don't want to.
> Thanks for the help,
> Nancy
> ----------------------------------------------------------
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