title: Performance of the FreeStyle Libre Flash glucose monitoring system in patients with type 1 and 2 diabetes mellitus.
abstract: OBJECTIVE
  To evaluate the performance of the FreeStyle Libre Flash continuous glucose monitoring (FSL-CGM) system against established central laboratory methods.
  
  
  METHODS
  20 subjects (8 type 1 diabetes mellitus, 12 type 2 diabetes mellitus) were analyzed. FSL-CGM sensor measurements (inserted in arm and abdomen) were compared with capillary blood glucose results analyzed with StatStrip as semigold standard. The glucose response after a standardized oral glucose load was measured by FSL-CGM and capillary samples analyzed by perchloric acid hexokinase (PCA-HK) method, StatStrip and FSL test strip (FSLC), and a commonly used CGM system (iPro2).
  
  
  RESULTS
  FSL-CGM arm sensor readings showed 85.5% of paired readings falling within Clarke Error Grid (ISO 15197:2013) zone A when compared with StatStrip. For FSL-CGM abdomen and FSLC, these percentages were 64% and 98%, respectively. The overall correlation of FSL-CGM in the arm and the StatStrip indicates a performance with lower results with the FSL-CGM in the arm than expected based on the StatStrip in the lower glucose ranges, and higher results than expected in the higher ranges. Following a standardized glucose load, a slower rise in glucose level was observed for FSL-CGM arm as compared with PCA-HK, StatStrip, FSLC, and iPro2 during the first 45-60 min after glucose load ingestion.
  
  
  CONCLUSIONS
  Certain matters need attention while using the FSL-CGM in daily life including the observed lower values in the lower ranges, and the underestimation of the effect of a meal on glucose response. These effects of such deviations can partly be overcome by optimizing the available user instructions.
  
  
  BACKGROUND
  TC5348; results.
authors.affiliation: Department of Clinical Chemistry , Isala , Zwolle , The Netherlands.
authors.forename: M J
authors.initials: MJ
authors.lastname: Fokkert
authors.affiliation: Isala, Diabetes Center, Zwolle, The Netherlands; Department of Internal Medicine, Isala, Zwolle, The Netherlands.
authors.forename: P R
authors.initials: PR
authors.lastname: van Dijk
authors.affiliation: Department Innovation and Science , Isala , Zwolle , The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Edens
authors.affiliation: Department of Clinical Chemistry , Isala , Zwolle , The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Abbes
authors.affiliation: Department Innovation and Science , Isala , Zwolle , The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: de Jong
authors.affiliation: Department of Clinical Chemistry , Isala , Zwolle , The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: Slingerland
authors.affiliation: Isala, Diabetes Center, Zwolle, The Netherlands; Department of Internal Medicine, Isala, Zwolle, The Netherlands; Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: H J G
authors.initials: HJ
authors.lastname: Bilo
keywords: Blood Glucose Self-Monitoring; Continuous Glucose Monitoring; Endocrinology Diabetes; Glucose Control