Patients may question the accuracy of their meter after comparing the results of tests done simultaneously on two different glucose meters. Questions to ask include:
• Are the test strips within the expiration date, and have they been stored properly?
• Has fresh control fluid been used to check the system? Most vials of control fluid expire 3 months after being opened. Often patients have not been taught the purpose or technique of quality-control testing. It is useful to keep control fluids for commonly used meters in the office and to check meters with questionable accuracy.
• Is their meter coded correctly for the currently used strips? Most meters must be recoded each time a new vial of strips is opened.
• Did the patient obtain an adequate drop of blood and properly apply the sample? Inadequate samples are the most common cause of inaccurate results. It is advised that each patient's technique be checked regularly. For patients who have trouble getting an adequate sample, the newer meters that use capillary action to obtain the sample are usually preferable to the traditional hanging-drop method.
• Is the patient aware of anything that might have damaged the meter?
• Is the patient comparing whole-blood and plasma-read meters? Comparing a
a meter's results with a lab measured plasma glucose is the only valid method for determining accuracy—a variance of less than 20% is considered acceptable meter performance. However, glucose meters use whole blood, and vein-drawn lab samples use the plasma portion. Newer meters mosdy report plasma glucose measurements, but there are still many on the market that report whole-blood results, which are approximately 12% lower. Each mode of measurement is considered accurate. However, meters that report plasma results are generally preferable for patients in intensive treatment programs to allow easier matching of meter-read and lab-measured glycemia values. Also, a useful practice for patients who have more than one meter is to use the same brand or at least the same manufacturer for ease in comparing results.
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Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...