title: A new-generation continuous glucose monitoring system: improved accuracy and reliability compared with a previous-generation system.
abstract: BACKGROUND
  Use of continuous glucose monitoring (CGM) systems can improve glycemic control, but widespread adoption of CGM utilization has been limited, in part because of real and perceived problems with accuracy and reliability. This study compared accuracy and performance metrics for a new-generation CGM system with those of a previous-generation device.
  
  
  METHODS
  Subjects were enrolled in a 7-day, open-label, multicenter pivotal study. Sensor readings were compared with venous YSI measurements (blood glucose analyzer from YSI Inc., Yellow Springs, OH) every 15 min (±5 min) during in-clinic visits. The aggregate and individual sensor accuracy and reliability of a new CGM system, the Dexcom(®) (San Diego, CA) G4™ PLATINUM (DG4P), were compared with those of the previous CGM system, the Dexcom SEVEN(®) PLUS (DSP).
  
  
  RESULTS
  Both study design and subject characteristics were similar. The aggregate mean absolute relative difference (MARD) for DG4P was 13% compared with 16% for DSP (P<0.0001), and 82% of DG4P readings were within ± 20 mg/dL (for YSI ≤ 80 mg/dL) or 20% of YSI values (for YSI >80 mg/dL) compared with 76% for DSP (P<0.001). Ninety percent of the DG4P sensors had an individual MARD ≤ 20% compared with only 76% of DSP sensors (P=0.015). Half of DG4P sensors had a MARD less than 12.5% compared with 14% for the DSP sensors (P=0.028). The mean absolute difference for biochemical hypoglycemia (YSI <70 mg/dL) for DG4P was 11 mg/dL compared with 16 mg/dL for DSP (P<0.001).
  
  
  CONCLUSIONS
  The performance of DG4P was significantly improved compared with that of DSP, which may increase routine clinical use of CGM and improve patient outcomes.
authors.affiliation: 1 Diablo Clinical Research , Walnut Creek, California.
authors.forename: Mark
authors.initials: M
authors.lastname: Christiansen
authors.forename: Timothy
authors.initials: T
authors.lastname: Bailey
authors.forename: Elaine
authors.initials: E
authors.lastname: Watkins
authors.forename: David
authors.initials: D
authors.lastname: Liljenquist
authors.forename: David
authors.initials: D
authors.lastname: Price
authors.forename: Katherine
authors.initials: K
authors.lastname: Nakamura
authors.forename: Robert
authors.initials: R
authors.lastname: Boock
authors.forename: Thomas
authors.initials: T
authors.lastname: Peyser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000209:etiology; D015374:Biosensing Techniques; D015190:Blood Glucose Self-Monitoring / Q000639:trends; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood* / Q000150:complications / Q000453:epidemiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000639:trends; D010349:Patient Compliance; D015203:Reproducibility of Results; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology