Tips for Accurate Blood Glucose Testing

People living with diabetes test their blood glucose anywhere from weekly to three to seven times daily or more. When performed properly, regular and frequent testing is an important self-management tool that can help diabetics avoid long-term risks and complications. However, even slight environmental variations can skew results and lead to problems including costly retesting and inaccurate adjustments to blood glucose levels.

Marc Wolf, a registered pharmacist with more than 28 years of experience serving diabetic patients and founder and CEO of Diabetic Care Services, offers testing supply storage, usage and testing procedure tips to ensure accurate readings from a home blood glucose test.

Testing Supply Storage

• Avoid storing meters and test strips in areas that experience varied temperatures, including heat, cold, sunlight or moisture. This can cause meters to produce error messages or damage chemical reagents on test strips, which can cause inaccurate readings.
• Only use test strips within 30 days of the date you first open the vial. Write the expiration date in permanent marker on the outside of the vial to help remember the date.
• Always store strips in their original vial and replace the vial cap immediately after removing the strips to avoid damage to strips, exposure to airborne contaminants and inaccurate readings.
• Never use strips that are stored in cracked or damaged bottles.

Testing Supply Usage
• Always use the test strip that is specific to your blood glucose meter to ensure compatibility. Some strips are physically but not chemically compatible with other meters, and will produce inaccurate readings. Follow meter instructions carefully for proper coding. Also, check that your meter batteries are fully charged, as low batteries can skew results.
• Ensure the meter is prepared to receive a blood droplet before drawing the sample.
• Avoid testing near rooms where there may be high levels of humidity-like the bathroom-as this can alter readings.
• Change lancets for every test, to avoid irritation from dull needles.

Test Site
• While some new meters allow for alternate site testing, the fingertip is the most accurate test site because it registers changes in blood glucose more quickly than the rest of the body. To avoid calluses, soreness and infection, prick the finger on the sides-not the pads-, alternating between different sides and all ten fingers.
• Properly clean testing site with soap and water before drawing a sample. Even the smallest bits of food, sugar and glucose tablet residue can alter a reading. Make sure the site is entirely dry because even water can affect results.
• Try to test at approximately the same time each day, which will make it easier for you to identify patterns or sudden changes in your results.

Blood Sample
• Dehydration can cause false high readings, so make sure you are properly hydrated before testing.
• Washing hands in warm water before testing can improve circulation and make it easier to obtain a sample. Pointing hands downward below heart level will also increase circulation.
• Gently squeezing and massaging your finger before pricking can increase blood flow, but do not squeeze finger immediately after prick, as this will actually decrease blood flow. Instead wait a moment and then gently milk the finger.
• When applying blood to the prepared test strip, avoid allowing your finger to touch the strip, as it may cause contamination. Make sure to fill the strip entirely; you may receive an error message if you do not.

After Testing
• Record results to compare levels before and after meals and between days. If you have trouble remembering to record results, use a meter that stores results in its memory. The WaveSense Jazz no code meter, available exclusively at www.diabeticcareservices.com and www.diabeticexpress.com, can hold up to 1,875 readings.
• If the test numbers do not coincide with how you are feeling, a personal indicator of where your general numbers should be, then test again. If you are still unsure, use an alternate meter. Do not ignore your intuition just to avoid retesting.

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