Findings published in the August 2004 issue of Diabetes Care indicate that a new analytical tool -- the Continuous Glucose Error-Grid Analysis (CG-EGA) -- which was created to evaluate the clinical accuracy of continuous glucose monitoring in people with diabetes, shows that continuous monitoring can provide highly accurate test results.
CG-EGA was developed by Boris Kovatchev, Ph.D., Linda Gonder-Frederick, Ph.D., Daniel Cox, Ph.D. and William Clarke, M.D. of the University of Virginia Health Systems. This group previously developed the Clarke Error- Grid Analysis, the current standard for evaluating the clinical accuracy of fingerstick blood glucose monitoring.
CG-EGA takes into account not just static point accuracy of glucose levels, but also directional accuracy, which tells patients whether their glucose levels are rising, falling or remaining steady.
"Continuous glucose sensor technology has the potential to revolutionize diabetes management by providing patients with ongoing, online feedback about current blood glucose levels and rate/direction of change, as well as alarms to alert for possible dangerous trends, such as rapid blood glucose descents that may lead to hypoglycemia," said William L. Clarke, M.D., Professor of Pediatrics in the Department of Pediatrics, Division of Endocrinology/Diabetes at the University of Virginia Health System in Charlottesville.
The Diabetes Care article cautions that evaluation of continuous glucose sensor accuracy is not straightforward, "especially if taken in the context of established accuracy measures." The article compares current fingerstick testing to still camera photography and likens continuous monitoring to video technology. "Thus, it would be inappropriate to gauge the accuracy of still cameras and camcorders using the same static measure...," the authors state.
The authors illustrated the applicability of CG-EGA using data collected during a clinical trial of Abbott Laboratories' Freestyle Navigator(TM) System, an investigational device designed to continuously monitor interstitial glucose levels that is under review by the U.S. Food and Drug Administration.
Dr. Clarke added, "Compared to a few self-monitoring blood glucose readings per day, the FreeStyle Navigator yielded detailed, directional results on a minute-by-minute basis."
"Continuous monitoring requires a paradigm shift in how patients and healthcare professionals think about and assess test results," said Ed Fiorentino, president of Abbott Diabetes Care, a division of Abbott Laboratories. "We believe that continuous glucose monitoring sensors, such as Navigator, have the potential to make a significant difference in the lives of people with diabetes. Education will play a key role in helping patients understand how to best take advantage of their potential."