The Clarke Error Grid Analysis (EGA) was developed in 1987 to quantify the clinical accuracy of patient estimates of their current blood glucose as provided by a blood glucose meter. This technique was then applied to quantify the clinical accuracy of blood glucose estimates generated by personal meters as compared to values from a laboratory reference test. A description of the EGA appeared in Diabetes Care in 1987. Eventually, the EGA became accepted as one of the “gold standard” techniques for determining the accuracy of blood glucose meters.