Continuous Glucose Monitoring

Education for Managed Care, Pharmacy, and Payer Professionals

Product Comparison for Self-Inserted Therapeutic CGM Systems

Product Attributes and Performance G6® CGM System (Dexcom)1 FreeStyle® Libre Flash Glucose Monitoring System (Abbott)2
CGM Classification Real-Time CGM Intermittent Scan CGM
Continuous data availability Data available without user intervention Data available only with user intervention (i.e. user must scan sensor)
Age indication (years) 2+ 18+
Confirmatory fingerstick required per labeled indications:    
– When experiencing symptoms that do not match sensor glucose readings Yes Yes
– When experiencing symptoms that may be due to low or high blood glucose No Yes
– During times of rapidly changing glucose (i.e., trend arrows↑↓) No Yes
– To confirm hypoglycemia or impending hypoglycemia as reported by the sensor No Yes
– Anytime the check BG icon appears No Yes
– During first 12 hours of sensor wear No Yes
Meets integrated CGM Class Criteria Yes No
FDA Classification/Pathway Relative Risk Designation Class II DeNovo6 Medium Risk Class III PMA7 High Risk
Meets Medicare therapeutic CGM criteria Yes Yes
Factory-calibrated Yes (manual calibration optional) Yes
Ease of use/sensor insertion No assembly required; 4 steps No assembly required; 3 steps
Sensor wear 10 days 14 days
Sensor life, adults >18 (% sensors working at end of maximum indicated use) 94% @ 10 days 71.6% @ 14 days
Sensor warm-up time 2 h 1 h
FDA approved sensor sites Abdomen (adults) Abdomen, upper buttocks (pediatrics) Upper arm
Protective Safeguards (alerts/alarms): – Predictive hypoglycemia alert Yes No
– Provides updates without user interaction (i.e. during sleep) Yes No
– Real-time, customizable glucose alerts (low/high) Yes No
– Rapidly rising/falling rate of change alerts Yes No
– Urgent low glucose safety alarm Yes No
Moisture protection Water resistant up to 8 feet for 24 h Water resistant up to 3 feet for 30 min
Insulin pump integration Yes; Tandem t:slim X2™ Yes; not commercially available
Smart insulin pen integration Yes; Companion InPen™ Yes; not commercially available
Communication range 20 feet 1.5 in
Mobile device connectivity Yes; iOS and Android via bluetooth Yes; iOS and Android can be used to scan sensor for data via near field communication
Remote monitoring Yes; continuous Yes; upon scanning3
Known interfering substances Hydroxyurea Ascorbic Acid at doses >500 mg may cause falsely higher readings; Salicylic Acid at doses >650 mg may cause falsely lower glucose values4
FDA Warning for Use in Hypoglycemia Unawareness Patients No Yes
Data storage Data automatically stored without user intervention Data stored when user scans the sensor. Sensor must be scanned at least once every 8 hours to prevent data loss
EHR Integration Capability Yes – Epic, Cerner (limited availability)  N/A
Overall accuracy MARD (average % discrepancy between CGM and reference YSI, 40-400 mg/dL) 9.0% (overall); 9.8% (adults); 7.7% (children) 10.1% (SSED data)
Hypoglycemia accuracy (Concurrence of sensor readings with YSI-measured values in the critically low range 40-60 mg/dL) 63% 25%
Accuracy during rapid rates of change (Concurrence of sensor readings with YSI- measured rates of change)
Rapidly Falling: > 2 mg/dL/min 53.3% 37.7%
Rapidly Rising: > 2 mg/dL/min 71.3% 40.4%


1Dexcom G6 CGM System User Guide 2018; 2Abbott FreeStyle Libre 14 day System User Guide 2018; Summary of Safety and Effectiveness Data (SSED), Abbott FreeStyle Libre, July 2018; 3Sharing function is not real-time (glucose information can only be viewed by the follower after the user scans their sensor with their smart device); 4Approach to Using Trend Arrows in the FreeStyle Libre Flash Glucose Monitoring Systems in Adults. Endocrine Society 2018; 5ADA Standards of Medical Care in Diabetes- 2020. 6FDA authorizes first Class II Interoperable CGM system. 7Class III PMA Approval for Abbott Freestyle Libre Flash Glucose Monitoring System