Clinical Outcomes
International diabetes experts recently collaborated to provide recommendations on how to optimize CGM-derived glucose data collection in clinical studies, including the specific glucose metrics and specific glucose metrics that should be evaluated. These consensus recommendations have been endorsed by key professional organizations, including the American Association of Clinical Endocrinologists, the American Diabetes Association, the Association of Diabetes Care and Education Specialists, Diabetes India, the European Association for the Study of Diabetes, the International Society for Pediatric and Adolescent Diabetes, the Japanese Diabetes Society, and the Juvenile Diabetes Research Foundation. This recommended standardized approach to CGM data collection and reporting in clinical trials will encourage the use of uniform metrics and enhance the interpretability of CGM data. Managed care and payer professionals should note that these metrics offer a body of useful information beyond HbA1c to inform therapeutic and treatment decisions, particularly related to hypoglycemia, postprandial hyperglycemia, and glucose variability.
Battelino T, Alexander CM, Amiel SA, et al. Continuous glucose monitoring and metrics for clinical trials: an international consensus statement. Lancet Diabetes Endocrinol. 2023;11:42-57.
Learn MoreThe 2023 Standards of Medical Care in Diabetes found Grade A evidence supporting the use of RT-CGM in adults with T1D or T2D on intensive insulin therapy and in adults with T2D on basal insulin. The American Diabetes Association (ADA) found Grade B evidence supporting the use of RT-CGM in children and adolescents with T1D on intensive insulin therapy and Grade E evidence for use of RT-CGM in children and adolescents with T2D on intensive insulin therapy. When used as an adjunct to pre- and postprandial BGM, RT-CGM can help to achieve HbA1c targets in pregnant patients with diabetes (Grade B). Based on input from experts, the ADA recommends continued access to RT-CGM through third party payers to people who have been using this technology.
American Diabetes Association. 7. Diabetes Technology: Standards of Care in Diabetes—2023. Diabetes Care. 2022; 46(Suppl 1):S111-S27.
Learn MoreDuring a session at the 20th World Congress on Insulin Resistance, Diabetes & Cardiovascular Disease held in December, Dr. Peter Reaven discussed the benefits of continuous glucose monitoring (CGM) beyond improved glycemic control. In an analysis of electronic health records from adults with type 1 diabetes (T1D) and type 2 diabetes (T2D) seen in Veterans Affairs (VA) clinics, use of CGM was associated with superior HbA1c reduction and a lower risk of hospitalization. The cohort included >50,000 adults with T1D or T2D who were either CGM users or non-users. CGM users with T1D had a lower risk of admissions to emergency rooms or hospitals for hypoglycemia-related events (HR=0.69 95% CI, 0.48, 0.98; P=0.04), a lower risk of hypoglycemia events in general (HR=0.72; 95% CI, 0.57-0.91; P=0.01), and a lower risk of all-cause hospitalization (HR=0.75; 95% CI, 0.63-0.9; P=0.002) than non-users. CGM users with T2D had a lower risk of hyperglycemia events (HR=0.87; 95% CI, 0.77-0.99; P=0.04) and all-cause hospitalization (HR=0.89; 95% CI, 0.82-0.97; P=0.004) than non-users. In a preliminary analysis, the researchers also calculated mortality risk using propensity score overlap weighting. CGM users with T1D had a lower risk for mortality at 18 months than non-CGM users (adjusted HR=0.38; 95% CI, 0.28-0.51; P<0.001). CGM users with T2D likewise had a reduced mortality risk compared with non-users (aHR=0.79; 95% CI, 0.7-0.88; P<0.001). Dr. Reaven noted that these findings signal a call-to-action for more widespread CGM use, giving managed care and payer professionals cause for consideration in developing coverage policies.
Reaven P. Presented at: 20th World Congress on Insulin Resistance, Diabetes & Cardiovascular Disease. December 1-3, 2022; Universal City, CA.
Learn MoreIn 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.
Learn MoreIn 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.
Learn MoreThe 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.
Learn MoreReal-time continuous glucose monitoring (RT-CGM) remains a key technologic advancement recommended for integration into the management of diabetes according to the American Diabetes Association (ADA) Standards of Care (SOC) 2022. ADA assigned Grade A evidence to the recommendation that RT-CGM be offered for diabetes management in adults with diabetes on multiple daily injections (MDI) of insulin or continuous subcutaneous insulin infusion (CSII). Similarly, the ADA assigned Grade A evidence to the recommendation that RT- CGM be used for diabetes management in adults with diabetes on basal insulin. ADA’s criteria for a Grade A designation is defined as clear evidence from well-conducted, generalizable randomized controlled trials that are adequately powered.
American Diabetes Association Professional Practice Committee, et al. 7. Diabetes Technology: Standards of Medical Care in Diabetes-2022. Diabetes Care. 2022;45(Suppl 1):S97-S112.
Learn MoreThe Wireless Innovation for Seniors with Diabetes Mellitus (WISDM) randomized clinical trial (RCT) featured a 26-week phase comparing real-time continuous glucose monitoring (RT-CGM) with blood glucose monitoring (BGM) in 203 adults aged ≥60 years with type 1 diabetes (T1D). Of the 198 participants who completed the RCT, 98% of RT-CGM group participants continued (CGM-CGM cohort) and 98% of BGM group participants crossed over to CGM (BGM-CGM cohort) for an additional 26 weeks. In the BGM-CGM cohort, median time <70 mg/dL decreased from 3.9% to 1.9% (P<0.001), TIR increased from 56% to 60% (P=0.006) and HbA1c decreased from 7.5% to 7.3% (P=0.025). Severe hypoglycemic events were reported for 9 participants while using BGM during the RCT and for only 2 participants during the extension phase with RT-CGM (P=0.02), indicating a sustained benefit of hypoglycemia avoidance in older adults out to 12 months.
Miller KM, et al. Benefit of Continuous Glucose Monitoring in Reducing Hypoglycemia Is Sustained Through 12 Months of Use Among Older Adults with Type 1 Diabetes. Diabetes Technol Ther. 2022;24(6):424-434.
Learn More