Comparison of Point Accuracy Between Two Widely Used Continuous Glucose Monitoring Systems

Abstract

Background: Safe and effective self-management of glucose levels requires immediate access to accurate data. We assessed the point accuracy of the Dexcom G7 Continuous Glucose Monitoring System (Dexcom, Inc., San Diego, CA, USA) and FreeStyle Libre 3 (Abbott Diabetes Care, Alameda, CA, USA) sensors in a head-to-head comparison. Method: Multicenter, single-arm, prospective, nonsignificant risk evaluation enrolled adults (≥ 18 years) with diagnosed type 1 diabetes (T1D) or type 2 diabetes (T2D). Accuracy was assessed by comparing sensor data to laboratory reference values Yellow Springs Instrument [YSI] and capillary blood glucose values. Outcome measures were differences in mean absolute relative difference (MARD), number and percentage of matched glucose pairs within ±20 mg/dL/±20 of reference values within glucose ranges: < 54, 54 to 69, 70 to 180, 181 to 250, > 250 mg/dL, and combined. Results: Data from 55 adults were included in the analysis. Analysis showed significantly lower MARD with the FreeStyle Libre 3 sensor vs the Dexcom G7 sensor (8.9% vs 13.6%, respectively, P < .0001) with a higher percentage of glucose values within ±20 mg/dL/±20 of reference (91.4% vs 78.6%). The MARD values for both continuous glucose monitoring (CGM) sensors were similar during the first 12 hours; however, the FreeStyle Libre 3 MARD was notably lower than the Dexcom G7 MARD during the next 12 hours (10.0% vs 15.1%, respectively, P < .0001) and throughout the study period. Conclusions: The FreeStyle Libre 3 sensor was more accurate than the Dexcom G7 sensor in all metrics evaluated throughout the study period. This is the first head-to-head study to our knowledge that compares the flagship products currently in widespread use of the two largest CGM manufacturers.

Differences in glucose readings between the continuous glucose monitoring calibration free interstitial sensors versus capillary blood glucose monitoring by glucometer: An analysis of two cases

“…While the parameters measured may not align directly with our study, two other studies have assessed the performance of these commercially available CGM systems in free-living settings, and have similarly observed deviations in the accuracy of the two systems from blood glucose measurements [ 5 , 8 ]. One study conducted by Hanson et al compared the latest CGM devices, specifically the Dexcom G7 and FreeStyle Libre 3 systems [ 8 ]. This single-arm study focused on adults diagnosed with either type 1 diabetes (T1D) or type 2 diabetes (T2D).…”

“…Making direct comparisons between our study findings and previously published ones is challenging due to differences in parameters measured. While we present our findings using simple mean and standard deviation, other studies have explored the accuracy of the CGM systems using the Mean Absolute Relative Difference (MARD) [ [3] , [4] , [5] , [6] , 8 ].…”

“…This single-arm study focused on adults diagnosed with either type 1 diabetes (T1D) or type 2 diabetes (T2D). Hanson et al reported that the Dexcom G7 exhibited a significantly higher MARD compared to the FreeStyle Libre 3 sensor, along with a higher bias and lower agreement with capillary blood glucose measurements [ 8 ]. Another study by Freckmann et al had similar observations and reported deviations of the Dexcom G5 and Freestyle Libre from blood glucose measurements [ 5 ].…”

Head-to-Head Evaluation of Continuous Glucose Monitoring and Automated Insulin Delivery Systems: Why are They not Used More Systematically?

“…In this issue of JDST, a study is published to present the results of an evaluation of the point accuracy between two different current CGM systems (Dexcom G7 vs FreeStyle Libre 3). 23 The results of this multicenter, single-arm, prospective, nonsignificant risk evaluation with 55 PwD with type 1 diabetes (T1D) or type 2 diabetes (T2D) showed lower MARD with the Libre 3 CGM system compared with the G7 system (8.9% vs 13.6%). The authors conclude that the Abbott CGM system is more accurate than the Dexcom system in all metrics evaluated.…”

Even Head-to-Head Comparison Studies of Continuous Glucose Monitoring System Performance Can be Biased

“…Hanson et al 1 recently published results from the first headto-head comparison study on the performance of the FreeStyle Libre 3 (FSL3; Abbott, Chicago, Illinois) and DexCom G7 (G7; DexCom, San Diego, California) continuous glucose monitoring (CGM) systems. Their results agreed well with the performance reported for the FSL3, but they showed substantial differences to the reported performance of G7.…”