HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: dc07-2401v1 31/6/1160    most recent Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Google Scholar Articles by Kovatchev, B. Articles by Clarke, W. PubMed PubMed Citation Articles by Kovatchev, B. Articles by Clarke, W. Social Bookmarking                What's this?

Comparison of the Numerical and Clinical Accuracy of Four Continuous Glucose Monitors

¹ University of Virginia, Charlottesville, Virginia
² Profil Institute for Metabolic Research, Neuss, Germany

Corresponding author: Boris Kovatchev, PhD, University of Virginia Health System, Box 800137, Charlottesville, VA 22901. E-mail: boris{at}virginia.edu

OBJECTIVE—The purpose of this study was to compare the numerical and clinical accuracy of four continuous glucose monitors (CGMs): Guardian, DexCom, Navigator, and Glucoday.

RESEARCH DESIGN AND METHODS—Accuracy data for the four CGMs were collected in two studies: Study 1 enrolled 14 adults with type 1 diabetes at the University of Virginia (UVA), Charlottesville, Virginia; study 2 enrolled 20 adults with type 1 diabetes at the Profil Institute for Metabolic Research, Neuss, Germany. All participants underwent hyperinsulinemic clamps including 1.5–2 h of maintained euglycemia at 5.6 mmol/l followed by descent into hypoglycemia, sustained hypoglycemia at 2.5 mmol/l for 30 min, and recovery. Reference blood glucose sampling was performed every 5 min. The UVA study tested Guardian, DexCom, and Navigator simultaneously; the Profil study tested Glucoday.

RESULTS—Regarding numerical accuracy, during euglycemia, the mean absolute relative differences (MARDs) of Guardian, DexCom, Navigator, and Glucoday were 15.2, 21.2, 15.3, and 15.6%, respectively. During hypoglycemia, the MARDs were 16.1, 21.5, 10.3, and 17.5%, respectively. Regarding clinical accuracy, continuous glucose–error grid analysis (CG-EGA) revealed 98.9, 98.3, 98.6, and 95.5% zones A + B hits in euglycemia. During hypoglycemia, zones A + B hits were 84.4, 97.0, and 96.2% for Guardian, Navigator, and Glucoday, respectively. Because of frequent loss of sensitivity, there were insufficient hypoglycemic DexCom data to perform CG-EGA.

CONCLUSIONS—The numerical accuracy of Guardian, Navigator, and Glucoday was comparable, with an advantage to the Navigator in hypoglycemia; the numerical errors of the DexCom were 30% larger. The clinical accuracy of the four sensors was similar in euglycemia and was higher for the Navigator and Glucoday in hypoglycemia.

Abbreviations: CG-EGA, continuous glucose–error grid analysis • CGM, continuous glucose monitor • EGA, error grid analysis • ISO, International Standards Organization • MAD, mean absolute difference • MARD, mean absolute relative difference • MedAD, median absolute difference • MedARD, median absolute relative difference • P-EGA, point–error grid analysis • R-EGA, rate–error grid analysis • UVA, University of Virginia

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				The Juvenile Diabetes Research Foundation Continuo Continuous Glucose Monitoring and Intensive Treatment of Type 1 Diabetes N. Engl. J. Med., October 2, 2008; 359(14): 1464 - 1476. [Abstract] [Full Text] [PDF]

				J. Brauker and B. Matsubara Comparison of the Numerical and Clinical Accuracy of Four Continuous Glucose Monitors: Response to Kovatchev et al. Diabetes Care, October 1, 2008; 31(10): e80 - e80. [Full Text] [PDF]