The accuracy of the FreeStyle Navigator continuous glucose monitoring system in children with type 1 diabetes

Diabetes Care. 2007 Jan;30(1):59-64. doi: 10.2337/dc06-1407.


Objective: To evaluate the accuracy and precision of the FreeStyle Navigator continuous glucose monitoring system in children with type 1 diabetes.

Research design and methods: In 30 children with type 1 diabetes (mean age 11.2 +/- 4.1 years), the Navigator glucose values were compared with reference serum glucose values of blood samples obtained in an inpatient clinical research center and measured in a central laboratory using a hexokinase enzymatic method and in an outpatient setting with a FreeStyle meter. Median absolute difference (AD) and median relative absolute difference (RAD) were computed for sensor-reference and sensor-sensor pairs.

Results: The median AD and RAD were 17 mg/dl and 12%, respectively, for 1,811 inpatient sensor-reference pairs and 20 mg/dl and 14%, respectively, for 8,639 outpatient pairs. The median RAD between two simultaneous Navigator measurements (n = 1,971) was 13%. Ninety-one percent of sensors in the inpatient setting and 81% of sensors in the outpatient setting had a median RAD < or = 20%.

Conclusions: The Navigator's accuracy does not yet approach the accuracy of current-generation home glucose meters, but it is sufficient to believe that the device has the potential to be an important adjunct to treatment of youth with type 1 diabetes.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Blood Glucose / analysis*
  • Child
  • Child, Preschool
  • Diabetes Mellitus, Type 1 / blood*
  • Exercise Test
  • Female
  • Humans
  • Inpatients
  • Male
  • Monitoring, Ambulatory / standards*
  • Outpatients
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Blood Glucose