Two things arrived on my desk just recently. One was a newspaper article stating that the Food and Drug Administration has asked the global body that sets requirements for home blood sugar meters to tighten its precision requirements. (A public conference on the subject is scheduled for March 16 and 17.) The other was a letter from a customer who explained how she had tried to compare two home glucometers with a plasma glucose measurement carried out in a laboratory — and how she was unnerved when she got three various readings.
Is Your Meter Accurate?
Stricter requirements for meter accuracy would be a welcome development: Currently, a lot of offered blood glucose meters are accurate only to within 10% to 15% of the real blood sugar level. However it will likely be a while prior to standards are changed and more precise meters become the norm.
In the meantime, there are steps you can take to get the best possible arise from your meter. One of the most important is to use only strips made for your meter and to use them properly. This includes making sure the strips have not passed their expiration date, coding your glucometer for each brand-new batch of strips (if you use a meter that needs coding), and bewaring to keep your strips in their original container, far from sources of heat, cold, or humidity. Improperly used or kept strips are among the most significant sources of mistake in home blood sugar monitoring. To inspect whether a batch of strips is OK, use a drop of the control service (unexpired!) that’s suitable with your meter on one of the strips in the batch.
If you still wish to check the accuracy of your glucometer by comparing it to a lab measurement, there is a method to do that. However getting meaningful results needs doing it right — both on your end and on the lab’s.
To explain how to do it right, I asked diabetes nurse professional and DSM Editorial Board member Virginia Peragallo-Dittko to upgrade some guidelines she’d composed for the magazine back in 2000, and here are the results:
Comparing Your Meter With the Lab
The best method to determine whether your meter readings are precise is to test them against the results you get from a lab. The innovative equipment in a lab allows professionals to make exact measurements. Don’t trouble comparing your meter to another home meter; neither system is considered a laboratory standard. If your self-monitoring results match the ones you get from the laboratory, you’ll know they’re accurate. If not, consult your diabetes teacher, who can help you determine what the problem is.
To compare glucometer and lab results, the two tests need to be done at the exact same time. In addition, you need to do the contrast with a fasting blood sugar sample. After-meal readings will vary in between capillary blood (used by your meter) and venous blood (used in the laboratory).
Prior to any blood is drawn, if you use a meter that has to be coded to the numbered great deal of strips, double-check that the code is proper. In addition, use a drop of control service on your meter’s test strip so you are sure that your test strips are not damaged.
When you and the professional are prepared, carry out a fingerstick check just prior to having actually blood drawn from your arm. (Doing the fingerstick after the blood is drawn from your arm is not practical considering that you might have to hold gauze to your arm after the venipuncture.) Doing a fingerstick at home either prior to or after the venipuncture enables excessive time in between the readings for a legitimate contrast.
Use a blood sample from your fingertip just for your meter reading. Do not use blood from an alternative site such as your lower arm, thigh, palm, or upper arm. Meter readings from these sites are not always identical to fingertip readings. Similarly, if the lab professional provides to place a drop of blood from the venipuncture needle onto your glucometer strip, do not accept the offer. Some strips are developed for capillary blood just and will offer false results if the venous blood is used.
For the functions of comparison, the venous blood that was collected into a tube should be spun by a centrifuge maker to separate the red blood cells from the plasma within 30 minutes after the time the blood sample was taken. If it is not, the glucose in the blood will begin to break down, and the outcomes will not properly show the blood sugar levels at the time the sample was gathered. (Note, nevertheless, that even if the sample is not centrifuged within 30 minutes, the results are still sufficient to detect diabetes or to signal your health-care provider to a problem with your diabetes control.)
Although you have no direct control over when the specimen is centrifuged, you can ask the laboratory technician about the time frame and demand that it be done within 30 minutes. Discuss that you are attempting to evaluate the precision of your meter which centrifuging within 30 minutes is a vital element of making that comparison. If the lab can guarantee you that centrifuging will be done within 30 minutes of the blood draw, you will have a valid comparison. If it can not, you should not bother to compare the two results.
Assuming you get the necessary assurance from the laboratory, make certain to make a note of your meter reading and flag it in some way so you know which glucometer reading to compare to your lab result when you get it. Under present requirements, your blood glucose meter is thought about accurate if its outcomes fall within 20% of the laboratory results.