Accuracy of a Fourth-Generation Continuous Glucose Monitoring System in Children and Adolescents with Type 1 Diabetes

Diabetes Technol Ther. 2018 Sep;20(9):576-584. doi: 10.1089/dia.2018.0109. Epub 2018 Jul 31.


Background: This study evaluated the safety and performance of the Guardian™ continuous glucose monitoring (CGM) system in children and adolescents with type 1 diabetes (T1D).

Materials and methods: Subjects 2-18 years of age (mean ± standard deviation [SD] 13.1 ± 3.9 years) with T1D and duration of diagnosis ≥1 year were enrolled at 11 sites in the United States and wore two Guardian Sensor 3 sensors in the abdomen and/or buttock. Sensors were connected to a transmitter paired with either a Guardian Connect system (i.e., mobile device with software application allowing display of sensor glucose [SG] values) or a Guardian Link 3 transmitter used as a Glucose Sensor Recorder (GSR). There were 145 participants who underwent a 6-h in-clinic frequent sample testing (FST) on day 1 (n = 54), day 3 (n = 48), or day 7 (n = 43) postsensor insertion. During FST, SG values were compared with a Yellow Springs Instrument (YSI) plasma reference every 5-15 min (n = 124, 7-18 years of age; n = 2, 2-6 years of age), or to a self-monitoring of blood glucose (SMBG) reference every 5-30 min (n = 19, 2-6 years of age).

Results: The overall mean absolute relative difference (ARD ± SD) between SG and reference values (YSI or SMBG) when calibrating approximately every 12 h, was 10.9% ± 10.7% (3102 paired points) for sensors communicating with the Guardian Connect system and 11.1% ± 10.6% (2624 paired points) for sensors connected to the GSR. The overall percentage of SG values within ±20% of reference values >80 mg/dL or within 20 mg/dL of reference values ≤80 mg/dL was 87.8% for the Guardian Connect system and 86.7% for the GSR, respectively. There was one device-related adverse event of contact dermatitis, but no serious device-related adverse events.

Conclusions: The Guardian CGM system demonstrated good accuracy in children and adolescents. These findings support its use in sensor-integrated insulin pump platforms, as well as a standalone technology, for managing diabetes in pediatric populations.

Trial registration: NCT01991470.

Keywords: Continuous glucose monitoring; MARD; Pediatrics; Sensor accuracy; Sensor-integrated pump.; mobile device.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Blood Glucose / analysis*
  • Blood Glucose Self-Monitoring / instrumentation*
  • Child
  • Child, Preschool
  • Diabetes Mellitus, Type 1*
  • Female
  • Humans
  • Male
  • Monitoring, Ambulatory / instrumentation*


  • Blood Glucose

Associated data