title: Comparison of accuracy and safety of the SEVEN and the Navigator continuous glucose monitoring systems.
abstract: OBJECTIVE
  This study evaluated the accuracy and safety of two continuous glucose monitoring (CGM) systems, the SEVEN (DexCom, San Diego, CA) and the Navigator (Abbott Diabetes Care, Alameda, CA), with the YSI laboratory measurements of blood glucose (blood glucose meter manufactured by YSI, Yellow Springs, OH), when worn concurrently in adults with type 1 diabetes.
  
  
  METHODS
  Fourteen subjects with type 1 diabetes, 33 +/- 6 (mean +/- SD) years old, were enrolled in this study. All subjects wore both sensors concurrently over three consecutive 5-day CGM sessions (15-day wear). On Days 5, 10, and 15, subjects participated in an 8-h in-clinic session where measurements from the CGM systems were collected and compared with YSI measurements every 15 min. At the end of Day 5 and 10 in-clinic sessions, the sensors were removed, and new sensors were inserted for the following CGM session despite the SEVEN system's recommended use for up to 7 days.
  
  
  RESULTS
  The mean absolute relative difference (ARD) for the two CGM devices versus YSI was not different: 16.8% and 16.1% for SEVEN and Navigator, respectively (P = 0.38). In the hypoglycemic region (YSI value <80 mg/dL), the mean ARD for SEVEN was lower than for Navigator (21.5% vs. 29.8%, respectively; P = 0.001). The data analyses were similar when compared with self-monitoring of blood glucose (SMBG) values. Thirteen additional Navigator replacement devices were issued compared to two for the SEVEN. A total of three versus 14 skin reactions were reported with the SEVEN and Navigator insertion area, respectively.
  
  
  CONCLUSIONS
  Glucose measurements with the SEVEN and Navigator were found to be similar compared with YSI and SMBG measurements, with the exception of the hypoglycemic range where the SEVEN performed better. However, the Navigator caused more skin area reactions.
authors.affiliation: Barbara Davis Center for Childhood Diabetes, School of Medicine, University of Colorado at Denver, Aurora, Colorado 80045, USA. satish.garg@ucdenver.edu
authors.forename: Satish K
authors.initials: SK
authors.lastname: Garg
authors.forename: James
authors.initials: J
authors.lastname: Smith
authors.forename: Christie
authors.initials: C
authors.lastname: Beatson
authors.forename: Benita
authors.initials: B
authors.lastname: Lopez-Baca
authors.forename: Mary
authors.initials: M
authors.lastname: Voelmle
authors.forename: Peter A
authors.initials: PA
authors.lastname: Gottlieb
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation / Q000379:methods*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004867:Equipment Design; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000175:diagnosis; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012449:Safety; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose