When used correctly, blood glucose
meters — small devices that measure and display your blood glucose
level — are usually accurate. But, occasionally they may be
incorrect. Often the inaccuracy is caused by human error. Many
people learn from the pharmacist and figure they know it all, but
they never read the booklet that comes with the meter. Then they
compound the problem by not reading the instructions that come with
the test strips.
The following chart shows some of the
problems:
Factors that affect accuracy |
Solutions |
Test strip problems |
Throw out damaged or outdated test strips. Store strips in
their sealed container; keep them away from heat, moisture and
humidity. Be sure the strips are meant for your specific glucose
meter. |
Extreme temperatures |
Keep your glucose meter and test strips at room temperature. |
Alcohol, dirt or other substances on your skin |
Wash your hands with soap and water (as hot as you can
tolerate). Dry your hands and the testing site thoroughly before
pricking your skin. |
Improper coding |
Some meters must be coded to each container of test strips.
Be sure the code number in the device matches the code number on
the test strip container. |
Meter problems |
Fully insert the test strip into the meter before pricking
your finger. Replace the meter battery as needed. |
Not enough blood applied to the test strip |
Move the test strip into a generous drop of blood. Let the
blood wick into the test strip and completely fill the area on
the test strip. Too little blood will cause an incorrect reading |
Testing site location |
If you're using a site other than your fingertip and you think
the reading is wrong, test again using blood from a fingertip.
Blood samples from alternate sites aren't as accurate as
fingertip samples when your blood sugar level is rising or
falling quickly. |
The amount of red blood cells in your blood |
If you are dehydrated or your red blood cell count is low
(anemia), your test results may be less accurate. |
If your meter isn't working properly,
contact the manufacturer of your meter and test strips.
Other common mistakes is dumping too
many test strips onto a dirty table and not using them in the
required time. Didn't read that did you? Yet, I have seen this done
by more people than I like. Only remove one strip from the test
strip container at a time and close the lid. Do not do this in
direct sunlight.
I have also seen this mistake done too
often. People put the test strip in the meter, then hunt for the
lancing device, and sometimes need to reassemble to lancing device
before they can use it. This means that the test strip has been out
too long and will probably give you an incorrect reading.
I suggest that you always have the
lancing device out and ready to use first. Then remove the test
strip from the container and close the lid. Then insert the test
strip into the meter slot and set it down to be able to prick your
side of a finger tip with the lancing device. Next pick up the
lancing device and prick the side of your finger near the tip of your
finger and make sure enough blood has risen to the surface. If
needed milk (gently squeeze) the finger to have enough of a blood
amount. Next set the lancing device down and pick up the meter with
the test strip already inserted and slide the test strip into the
blood at a 10 to 20 degree angle and let the blood wick into the test
strip. Make sure that enough blood has completely filled the area of
the test strip to obtain an accurate reading.