Characterizing Accuracy and Precision of Glucose Sensors and Meters. (September 2014)

• Record Type: Journal Article
• Authors: Rodbard, David
• Is Part Of: Journal of diabetes science and technology. Volume 8:Number 5(2014)
• Page Start: 980
• Page End: 985
• Publication Date: 2014-09
• Subjects: diabetes mellitus type 1 -- diabetes mellitus type 2 -- glucose monitoring -- continuous glucose monitoring -- self-monitoring of blood glucose -- accuracy -- precision -- mean absolute relative deviation (MARD) -- precision absolute relative deviation (PARD) -- bias -- Clarke error grid -- Parkes error grid -- Bland–Altman plot -- statistical analysis; Diabetes -- Periodicals; Medical technology -- Periodicals; Diabetes Mellitus -- Periodicals; 616.462005
• DOI: 10.1177/1932296814541810
• Languages: English
• ISSNs: 1932-2968

Abstract

There is need for a method to describe precision and accuracy of glucose measurement as a smooth continuous function of glucose level rather than as a step function for a few discrete ranges of glucose. We propose and illustrate a method to generate a "Glucose Precision Profile" showing absolute relative deviation (ARD) and /or %CV versus glucose level to better characterize measurement errors at any glucose level. We examine the relationship between glucose measured by test and comparator methods using linear regression. We examine bias by plotting deviation = (test – comparator method) versus glucose level. We compute the deviation, absolute deviation (AD), ARD, and standard deviation (SD) for each data pair. We utilize curve smoothing procedures to minimize the effects of random sampling variability to facilitate identification and display of the underlying relationships between ARD or %CV and glucose level. AD, ARD, SD, and %CV display smooth continuous relationships versus glucose level. Estimates of MARD and %CV are subject to relatively large errors in the hypoglycemic range due in part to a markedly nonlinear relationship with glucose level and in part to the limited number of observations in the hypoglycemic range. The curvilinear relationships of ARD and %CV versus glucose level are helpful when characterizing and comparing the precision and accuracy of glucose sensors and meters.