Background: Accuracy of a seventh-generation "G7" continuous glucose monitoring (CGM) system was evaluated in children and adolescents with type 1 diabetes (T1D).
Methods: Sensors were worn on the upper arm and abdomen. The CGM data were available from 127 of 132 participants, ages 7 to 17 years, across 10.5 days of use, various glucose concentration ranges, and various rates of glucose change for comparisons with temporally matched venous blood glucose measurements (YSI). Data were also available from 28 of 32 participants, ages 2 to 6 years, for whom capillary (fingerstick) blood provided comparator glucose values. Accuracy metrics included the mean absolute relative difference (MARD) between CGM and comparator glucose pairs, the proportion of CGM values within 15 mg/dL or 15% of comparator values <100 or ≥100 mg/dL, respectively, and the analogous %20/20 and %30/30 agreement rates.
Results: For participants aged 7 to 17, a total of 15 437 matched pairs were obtained from 122 arm-placed and 118 abdomen-placed sensors. For arm-placed sensors, the overall MARD was 8.1% and overall %15/15, %20/20, and %30/30 agreement rates were 88.8%, 95.3%, and 98.7%, respectively. For abdomen-placed sensors, the overall MARD was 9.0% and overall %15/15, %20/20, and %30/30 agreement rates were 86.0%, 92.9%, and 97.7%, respectively. Good accuracy was maintained across wear days, glucose ranges, and rates of glucose change. Among those aged 2 to 6, a total of 343 matched pairs provided an overall MARD of 9.3% and an overall %20/20 agreement rate of 91.5%.
Conclusions: The G7 CGM placed on the arm or abdomen was accurate in children and adolescents with T1D. NCT#: NCT04794478.
Keywords: Dexcom; G7; MARD; accuracy; continuous glucose monitoring; pediatrics.