title: Accuracy evaluation of five blood glucose monitoring systems: the North American comparator trial.
abstract: BACKGROUND
  This study evaluated differences in accuracy between the CONTOUR® NEXT EZ (EZ) blood glucose monitoring system (BGMS) and four other BGMSs [ACCU-CHEK® Aviva (ACAP), FreeStyle Freedom Lite® (FFL), ONE TOUCH® Ultra®2 (OTU2), and TRUEtrack® (TT)].
  
  
  METHODS
  Up to three capillary blood samples (N = 393) were collected from 146 subjects with and without diabetes. One sample per subject was tested with fresh (natural) blood; the other samples were glycolyzed to lower blood glucose to <70 mg/dl. Meter results were compared with results from plasma from the same sample tested on a Yellow Springs Instruments (YSI) 2300 STAT PlusTM glucose analyzer. Blood glucose monitoring system accuracy was compared using mean absolute relative difference (MARD; from laboratory reference method results) and other analyses. Separate analyses on fresh (natural) samples only were conducted to determine potential effects of glycolysis on MARD values of systems utilizing glucose-oxidase-based test strip chemistry.
  
  
  RESULTS
  Across the tested glucose range, the EZ had the lowest MARD of 4.7%; the ACAP, FFL, OTU2, and TT had MARD values of 6.3%, 18.3%, 23.4%, and 26.2%, respectively. For samples with glucose concentrations <70 mg/dl, the EZ had the lowest MARD (0.65%), compared with the ACAP (2.5%), FFL (18.3%), OTU2 (22.4%), and TT (33.2%) systems.
  
  
  CONCLUSIONS
  The EZ had the lowest MARD across the tested glucose ranges when compared with four other BGMSs when all samples were analyzed as well as when natural samples only were analyzed.
authors.affiliation: Bayer HealthCare LLC, Diabetes Care, 555 White Plains Rd., Tarrytown, NY 10591. solveig.halldorsdottir@bayer.com.
authors.forename: Solveig
authors.initials: S
authors.lastname: Halldorsdottir
authors.forename: Mary Ellen
authors.initials: ME
authors.lastname: Warchal-Windham
authors.forename: Jane F
authors.initials: JF
authors.lastname: Wallace
authors.forename: Scott
authors.initials: S
authors.lastname: Pardo
authors.forename: Joan Lee
authors.initials: JL
authors.lastname: Parkes
authors.forename: David A
authors.initials: DA
authors.lastname: Simmons
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation* / Q000592:standards*; D003920:Diabetes Mellitus / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States; D055815:Young Adult
chemical_list: D001786:Blood Glucose