HOW ACCURATE ARE BLOOD GLUCOSE METERS?
March 3, 2022 - A vast array of glucose meters are available to the general public today. Some devices make Bluetooth connections to phones and send readings to apps for charting and sharing. Some meters are thumbnail-sized devices that plug into smartphones for easy transport. The FreeStyle Libre measures glucose levels by waving a smartphone over a patch that is worn for 14 days. Bells and whistles are nice, but unless the meter delivers accurate readings, it is useless.
So how does someone know if the meter they are buying is accurate? The FDA requires that meter manufacturers meet a standard referred to as ISO 15197, which states that 95% of the meter's readings must be within 15% of a reference standard for blood sugars greater than 100 mg/dl and within 15 mg/dl for readings less than 100 mg/dl. Despite this requirement, independent aftermarket testing has found that many meters don't meet the standard.
Two studies have been published within the past five years that looked at the accuracy of over 18 meters. We combined results from those studies and put them in a chart that is available at the link below. A pdf version of the chart is also included.