Performance of a Factory-Calibrated Real-Time Continuous Glucose Monitoring System Utilizing an Automated Sensor Applicator

Background: This study assessed the accuracy of a factory-calibrated 10-day real-time continuous glucose monitoring (CGM) system (G6), which includes an automated sensor applicator. Methods: Seventy-six participants with insulin-treated diabetes were enrolled at four U.S. sites as part of a larger study of G6 system performance. In-clinic visits for frequent comparative blood glucose measurements using a reference instrument (YSI) were conducted on days 1, 4-5, 7, and/or 10 of system use. Accuracy evaluation included the proportion of CGM values that were within 20% of YSI reference value for glucose levels >100mg/dL and 20mg/dL for YSI glucose levels 100mg/dL (%20/20), the analogous %15/15 and %30/30, and the mean absolute relative difference (MARD) between temporally matched CGM and YSI values. Participants calibrated the systems once daily. Raw sensor data were reprocessed using assigned sensor codes and a factory-calibration algorithm. Results: Reprocessed data from 62 participants (25 adults and 37 children and adolescents of ages 6-17 years; 3532 YSI-CGM pairs) were analyzed. The G6 system's overall %20/20 was 93.9% (adults, 92.5%; children and adolescents, 96.2%), its %15/15 was 83.3% (adults, 78.3%; children and adolescents, 91.1%), and its MARD was 9.0% (adults, 9.8%; children and adolescents, 7.7%). Overall day-1 %20/20 accuracy was 92.2%, %15/15 was 81.5%, and MARD was 9.3%. Accuracy was maintained across 10 days of use and various glucose concentration ranges in both adults and children and adolescents. Conclusions: The G6 system utilizing an automated sensor applicator provides accurate glucose readings in adults and children and adolescents throughout the 10-day sensor life.