Evaluation of a New Blood Glucose Monitoring System with Auto-Calibration

Abstract

The Ascensia CONTOUR System (Bayer HealthCare LLC, Elkhart, IN) is a new blood glucose (BG) monitoring system (BGMS) that uses glucose dehydrogenase chemistry and that combines low sample volume, fast response time, an auto-control marking feature, and an auto-calibration function in a small package. The system was evaluated at four diabetes clinics with ambulatory subjects who had diabetes. The BGMS was tested by both health care professionals (HCPs) and lay users. It was also evaluated at high altitude (10,200 feet) and, in conjunction with the Ascensia MICROLET VACULANCE (Bayer), for use with samples obtained from four alternative anatomical sites. When the system was used with blood from fingersticks, both lay users and HCPs obtained results that fulfilled the International Organization for Standardization (ISO) 15197:2003 accuracy criteria, which advocate that 95% of BG measurements should fall within +/-15 mg/dL (for BG concentrations <75 mg/dL) or +/-20% (for BG concentrations > or = 75 mg/dL) of the laboratory value. Lay users obtained 96.9% of glucose results, and HCPs obtained 96.4% of glucose results, within ISO accuracy criteria. People with diabetes who had no prior experience using the system also obtained acceptable results (97.0%), as did the HCP using fingerstick samples from subjects in the high altitude study (97.0%). Among the alternative anatomical sites tested, only the results from the palm met the ISO criteria (97.5%), although the results from all four sites (palm, thigh, abdomen, and forearm) were clinically acceptable when assessed using error grid analysis. Most subjects rated the BGMS as either excellent or very good in a questionnaire, and were able to use it properly without training. These findings indicate that the Ascensia CONTOUR System, which does not require calibration by the user, is a convenient and accurate instrument with useful features for people who routinely monitor BG.