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Measurement accuracy of blood glucose monitoring versus continuous glucose monitors

Devices – January 2019 digest

Study comparing the performance of continuous glucose monitoring systems with blood glucose measurements.

Freckmann G, Link M, Pleus S et al (2018) Measurement performance of two continuous tissue glucose monitoring systems intended for replacement of blood glucose monitoring. Diabetes Technol Ther 20: 541–9

  • Continuous glucose monitoring (CGM) systems take more readings than blood glucose measurements and therefore support the assessment of metabolic control and can identify glycaemic trends.
  • This head-to-head study compared the performance of the Dexcom G5 Mobile real-time CGM system and the Free-Style Libre flash glucose monitoring system with the standard approach of blood glucose monitoring under real-life and clinical conditions.
  • Twenty participants with type 1 diabetes measured their blood glucose levels over a 2-week period in different settings (site visits, home use and during phases of induced rapid glucose changes) using the Dexcom G5 Mobile and the Free-Style Libre. They also took blood glucose measurements and made therapeutic decisions based on these readings alone.
  • About a quarter of Dexcom G5 and Free-Style Libre results differed by more than 0.8 mmol/L or 15% from blood glucose monitoring results at therapeutic decision points, and approximately 5% of the differences measured were greater than 1.7 mmol/L or 30%.
  • The performance of the CGM systems differed depending on the setting.  
  • Deviations in blood glucose readings should be taken into account when using CGM systems. 

Click here to access the study in full.

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