Sources of error

Mistakes at measuring your blood glucose can lead to wrong results. There are multiple causes: operating problems with the meter, defective test strips or meters, different interferences.
 
The patient has to be trained to use the meter and the test strips to avoid problems. Using a meter is normally very easy and the training can be done quickly.
 
Tests with control solution from time to time ensure best quality of the blood glucose testing. It makes sense to perform a test with control solution when opening a new vial of test strips, if the meter dropped down or was somehow damaged, if the test results do not reflect your personal feeling or if results are somehow suspect.  
 
 
Possible sources of error
Most problems are caused by mistakes during operation. Only on rare occasions meter, test strips or other interferences cause problems.
 
Damaged test strips
Test strips should not be exposed to direct sunlight, extreme humidity, cold or warm temperatures and should not be used after expiration date. These sensible diagnostics have to stored in the original vials, which should be closed immediately after taking out one strip.
 
Damaged meter
Blood glucose meters are high precision instruments and should be handled after the instructions of the manufacturer. The meter is operated with sufficiently charged batteries. Correct insertion of the test strip has to be checked.
 
Handling errors
Operation of a new meter has to be trained. The correct sampling of a blood drop should be educated as well.
 

• If the finger is pressed too much the blood sample will be diluted with liquids from the tissue which can lead to wrong results.

• Wash your hands thoroughly to avoid pollution of the blood sample with residues from food and for hygienic reasons.

• Dry hands thoroughly to avoid dilution of the blood sample with water.

• Disinfection is not needed.

• The size of the blood sample has to be sufficient to enable a correct testing at the reaction zone of the test strip.

• Do not move the test strip during the testing procedure.

• If using a meter which has to be coded do not forget to set the new code when opening a new vial of test strips.

• Heat, direct sunlight, extrem high humidity in the air (water steam) or extreme cold temperature harm meter and test strips.

Other interferences
 
Both substances from the body and from outside (medication e.g.  vitamin C, Acetyl salicylic acid,..) can influence accuracy of the test  results. Values can deviate to higher or lower results. Please refer to  Instruction for Use of your meter and your test strips.
 
Test results can be incaccurate if a person has very high or very low hematocrite levels.
 
After intensive loss of water (strong diarrhoea or nausea) test results can be inaccurate.
 
Residues of disinfecting agents have to completely disappear to avoid inaccurate results.
 
Contact your diabetes health care team for further information.