Are You Getting Consistently Accurate Glucose Readings?
Even when our glucose monitors are well calibrated and functioning properly, there are several factors that can affect the accuracy of blood sugar readings.
To consistently obtain the most accurate readouts possible, meter users need only take simple precautions, and cultivate a few not-too-time-consuming habits:
- Store your test strips at room temperature in a sealed container, away from moisture and humidity. Make sure the strips you have are meant for use with your brand of meter, and toss out strips that are outdated or damaged. Using a glucose control solution* every time a new strip container is opened, and at subsequent regular intervals, is recommended.
- Store your glucose meter at room temperature, preferably away from moisture and humidity. Keep extra batteries on hand and replace them as needed. If your device must be coded to each container of test strips, make sure the code number on the container matches the number in your meter. Using a glucose control solution* is recommended if the meter is dropped.
- Before monitoring, thoroughly wash and dry your hands, and the test site. Any substance on the skin - alcohol, dirt, oils - can diminish the accuracy of a reading.
- When testing, make sure the test strip is fully inserted into the monitor. Touch a generous drop of blood to the strip—not enough blood may lead to a faulty reading. Do not add more blood to a test strip once the first drop is applied.
- If you suspect a reading is wrong and used a site other than a fingertip, test again from a fingertip. When blood sugar levels are rapidly rising or falling, fingertip samples are more accurate than alternate site samples.
Also, be aware that dehydration, or having anemia (red blood cell deficiency) can lead to less than accurate monitoring results.
Besides occasionally using a control solution to check your meter’s accuracy, take it with you to your next doctor or blood-draw appointment. Use the meter to check your glucose level at the time your blood is drawn for testing. You can then compare your meter’s readout with the lab results. Readings within 15 percent of lab outcomes are considered accurate for portable monitoring devices.
*A glucose control solution, available at most drugstores and pharmacies, contains a known amount of glucose. A drop of the solution is placed on a test strip, instead of blood, so the meter can read the solution’s glucose level. If all is working well, the meter will indicate the control solution is within range, or the glucose level will match a range written on the test strip vial.