title: Accuracy of the modified Continuous Glucose Monitoring System (CGMS) sensor in an outpatient setting: results from a diabetes research in children network (DirecNet) study.
abstract: OBJECTIVE
  We previously reported the results of an inpatient accuracy study in children with type 1 diabetes using the Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed, Northridge, CA). During the course of that study, a new process was implemented for manufacturing the CGMS sensor. Accuracy from the resulting modified sensor used by only 14 children was significantly better than the original version [median relative absolute difference (RAD), 11% vs. 19%; P < 0.001]. Baseline data from a subsequent outpatient study provide an opportunity to further assess the accuracy of the modified sensor in a much larger sample of children with type 1 diabetes.
  
  
  METHODS
  As part of a randomized trial to assess the utility of the GlucoWatch G2 Biographer (Cygnus, Inc., Redwood City, CA), 200 children with type 1 diabetes were instructed to wear a CGMS for 48-72 h in an outpatient setting at baseline. Glucose measurements from a OneTouch UltraSmart (Lifescan, Inc., Milpitas, CA) home glucose meter were downloaded and used as reference values to calculate accuracy measures.
  
  
  RESULTS
  The overall median RAD was 12%. Accuracy was better during hyperglycemia than during hypoglycemia (median RAD, 10% vs. 20%; P < 0.001) and on optimal versus non-optimal days but did not vary significantly by the number of calibrations entered.
  
  
  CONCLUSIONS
  These data confirm the improved accuracy previously reported for the modified version of the CGMS sensor.
authors.affiliation: DirecNet Coordinating Center, Jaeb Center for Health Research, Tampa, FL 33647, USA. direcnet@jaeb.org
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Tansey
authors.forename: Roy W
authors.initials: RW
authors.lastname: Beck
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Buckingham
authors.forename: Nelly
authors.initials: N
authors.lastname: Mauras
authors.forename: Rosanna
authors.initials: R
authors.lastname: Fiallo-Scharer
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Xing
authors.forename: Craig
authors.initials: C
authors.lastname: Killman
authors.forename: William V
authors.initials: WV
authors.lastname: Tamborlane
authors.forename: Katrina J
authors.initials: KJ
authors.lastname: Ruedy
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring / Q000379:methods; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D006801:Humans; D018670:Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D001786:Blood Glucose
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