In 1987, William Clarke developed The Clarke Error Grid Analysis (EGA) system to quantify clinical accuracy of glucose meters compared to actual blood glucose levels of the patients using them

1. In 1987, William Clarke developed The Clarke Error Grid Analysis (EGA) system to quantify clinical accuracy of glucose meters compared to actual blood glucose levels of the patients using them.
An EGA graph below has five sections:
-Region A where values are within 20% actual levels
-Region B are points outside of 20% but would not lead to inappropriate treatment,
-Region C are points that lead to unnecessary treatment,
-Region D are points where potentially dangerous failure to detect hypoglycemia or hyperglycemia exist
-Region E are points that would confuse treatment of hypoglycemia for hyperglycemia and vice-versa.