The U.S. Food and Drug Administration has issued new guidelines for manufacturers of home glucose monitoring devices. The old standard was that the glucose reading of the device had to be within 20% of the actual or true value compared to a medical lab-grade machine.
For example, if the device read 165 mg/dl, the true value could be anywhere from 132 to 198 mg/dl.
Under the new +/- 15% rule, the true number should be between 140 and 190 mg/dl.
I bet you thought your device was more accurate than that.
From the FDA to device manufacturers:
“Blood glucose test results are used by people with diabetes to make critical decisions about their treatment; therefore, it is important that the results are accurate so that nutritional and drug dosing errors are better avoided. Your studies should demonstrate that your SMBG [self-monitoring of blood glucose] is sufficient for this purpose by showing that 95% of all SMBG results in this study are within +/- 15% of the comparator results across the entire claimed measuring range of the device and that 99% of all SMBG results are within +/- 20% of the comparator results across the entire claimed measuring range of the device.”