Factors That Affect Glucose Meter Performance

The accuracy of your test results depends partly on the quality of your meter and test strips and your training. Other factors can also make a difference in the accuracy of your results.

Hematocrit. Hematocrit is the amount of red blood cells in the blood. Patients with higher hematocrit values will usually test lower for blood glucose than patients with normal hematocrit. Patients with lower hematocrit values will test higher. If you know that you have abnormal hematocrit values you should discuss its possible effect on glucose testing (and HbA1C testing) with your health care provider. Anemia and Sickle Cell Anemia are two conditions that affect hematocrit values.

Other Substances. Many other substances may interfere with your testing process. These include uric acid (a natural substance in the body that can be more concentrated in some people with diabetes), glutathione (an "anti-oxidant" also called "GSH"), and ascorbic acid (vitamin C). You should check the package insert for each meter to find what substances might affect its testing accuracy, and discuss your concerns with your health care provider.

Altitude, Temperature and Humidity. Altitude, room temperature, and humidity can cause unpredictable effects on glucose results. Check the meter and test strip package insert for information on these issues. Store and handle the meter and test strips according to the instructions.

Third-Party Test Strips. Third-party or "generic glucose reagent strips" are test strips developed as a less expensive option than the strips that the manufacturer intended the meter to be used with. They are typically developed by copying the original strips. Although these strips may work on the meter listed on the package, they could look like strips used for other meters. Be sure the test strip you use is compatible with your glucose meter.

Sometimes manufacturers change their meters and their test strips. These changes are not always communicated to the third-party strip manufacturers. This can make third-party strips incompatible with your meter without your knowledge. Differences can involve the amount, type or concentration of the chemicals (called "reagents") on the test strip, or the actual size and shape of the strip itself. Meters are sensitive to these features of test strips and may not work well or consistently if they are not correct for a meter. If you are unsure whether or not a certain test strip will work with you meter, contact the manufacturer of your glucose meter.