Author: Julia Vetsikas

In an analysis of available data, accuracy metrics from preapproval trials of the G5, G6, and G7 real-time continuous glucose monitoring (RT-CGM) systems were compared after propensity score adjustments were applied to balance baseline demographic characteristics. Metrics included mean absolute relative differences (MARD) between CGM and YSI values (from the YSI, Inc., 2300 Stat Plus system) and the proportion of CGM values within 20% or 20 mg/dL of the YSI values (“%20/20”). Ease-of-use was also evaluated by formal task analysis in the study. Accuracy performance of the G7 sensors, whether placed on the arm or abdomen, was similar to that of abdomen-placed G5 and G6 sensors, and egregious errors were rare with all three systems. Based on the formal task analysis, the authors concluded that simplification of the sensor insertion process should result in G7 being even easier to learn and several software improvements may contribute to better glycemic outcomes. Payer professionals may well find confidence in the comparative usability data for the latest RT-CGM system versus previous versions of the technology when considering updates to coverage policies.

Welsh JB, Psavko S, Zhang X, Gao P, Balo AK. Comparisons of Fifth-, Sixth-, and Seventh-Generation Continuous Glucose Monitoring Systems. J Diabetes Sci Technol. 2022:19322968221099879.

In children and adolescents with type 1 diabetes (T1D), the G7 real-time continuous glucose monitoring (RT-CGM) system demonstrated accuracy across wear days, glucose ranges, and rates of glucose change. Over 10.5 days, RT-CGM data from 28 participants aged 2 to 6 years and 127 participants aged 7 to 17 were collected and compared with blood glucose measurements. In young children aged 2 to 6, overall MARD and %20/20 agreement rates were 9.3% and 91.5%, respectively. In older children and adolescents aged 7 to 17 years, arm- and abdomen-placed G7 sensor MARD values were 8.1% and 9.0%, respectively, and overall %20/20 values were 95.3% and 92.9%, respectively. These results are consistent with those of the G6 system in children and adolescents with T1D and with an earlier study of the G5 system that evaluated accuracy at different insertion sites. Compared with the G6 RT-CGM system, the G7 has a shorter warm-up period (27 minutes vs 2 hours), making it possible for youth and caregivers of young children to obtain glucose data more quickly for diabetes management decisions. According to the authors, while day 1 accuracy tends to be lower across CGM devices, the accuracy of the G7—coupled with its shorter warm-up period—should improve the sensor experience in young users. The G7 RT-CGM was recently FDA approved for use in all individuals with diabetes aged 2 years and older, and having data specific to use in children and adolescents can be of value for managed care and payer professionals in developing coverage policies.

Laffel LM, Bailey TS, Christiansen MP, Reid JL, Beck SE. Accuracy of a Seventh-Generation Continuous Glucose Monitoring System in Children and Adolescents with Type 1 Diabetes. J Diabetes Sci Technol. 2022:19322968221091816.

The accuracy and safety of the G7 real-time continuous glucose monitoring (RT-CGM) system was demonstrated over 10.5 days of use in adults with diabetes. In the study, adults with either type 1 or type 2 diabetes—either on intensive insulin therapy or not—wore G7 sensors concurrently on the upper arm and abdomen. Individuals were seen in clinic on days 1 or 2, 4 or 7, and on the second half of day 10 or the first half of day 11 for frequent comparisons with comparator blood glucose measurements obtained with the YSI 2300 Stat Plus glucose analyzer. After analyzing data from 316 participants (619 sensors, 77,774 matched pairs), overall mean absolute relative differences (MARD) between RT-CGM and YSI values for arm- and abdomen-placed sensors were 8.2% and 9.1%, respectively. In-clinic glucose manipulations and frequent blood glucose sampling confirmed accurate readings during euglycemia, hypoglycemia, and hyperglycemia (reflected as time in range [TIR], time below range [TBR], and time above range [TAR]), as well as during rapid glucose concentration change. Even at the highest rates of glucose concentration change, MARD values <10% were observed for arm-placed sensors and were <10.5% for abdomen-placed sensors. Offering a smaller size and added features, such as sensor/transmitter integration with a simplified insertion process, the G7 also demonstrated a favorable safety profile, with no serious adverse events reported during the study. With the recent FDA approval of the G7 RT-CGM system, payer professionals may well find value in the accuracy and safety data from this prospective multicenter single-arm study when they are developing coverage criteria.

Garg SK, et al. Accuracy and Safety of Dexcom G7 Continuous Glucose Monitoring in Adults with Diabetes. Diabetes Technol Ther. 2022;24(6):373-380.