Presentation Abstract

Presentation Number: 1005
Title: How accurate are blood glucose meters used for patient self testing
Authors: M.J. O'Kane, M. McCloskey, C. Diver-Hall;
Clinical Translational Research and Innovation Centre, Londonderry, UK.
Keyword: 45 Devices
Abstract: Background and aims: There is increasing concern being expressed about the accuracy of glucose meters used both in hospitals and for self-testing. A number of endogenous and exogenous substances can influence the accuracy of results and as such several bodies (ISO, IFCC, FDA) are looking at revised performance criteria for glucose meter performance. The purpose of this study was to challenge the analytical performance of commonly used SMBG meters and to compare the clinical performance of the best and worst performing meters.
Materials and methods: Seven SBGM meters (NovaMax plus, Glucofix Mio plus. Glucomen Lx plus, AccuCheck Aviva, Ascencia Breeze 2, Optium Xceed, and OneTouch Ultra 2 were tested. The meters were challenged with differing hematocrit levels and differing levels of non-glucose sugars (maltose, galactose, xylose) and at five different glucose concentrations (1.1-3.3, 5.5-8.3, 11.1-16.7, 18.1 - 22.2 and 23.6-27.8 mmol/L). Each individual sample was tested 6 times with each meter. Results were compared to the YSI reference method and the mean bias deviation calculated for each meter. The imprecision of each meter was determined at three different levels and this was used in conjunction with the bias deviation to calculate mean total error (%bias + 1.65 CV(%). A method correlation was performed using a spiked sample panel. The meters showing the best and poorest total errors were selected for a study performed on capillary samples collected from self-testing diabetic outpatients.
Results: An example of the mean total error rates for all glucose meters at a glucose range of 11.1-16.7 mmol/L is presented in the Table. The Nova Max plus, Glucofix mio and Glucomen Lx were unaffected by the interferences assessed and demonstrated low and acceptable total error rates. The other meters were affected to varying levels by the interfering substances. The Nova Max plus, Glucofix mio and Glucomen Lx and One Touch Ultra were selected for diabetic patient testing. Initial data shows that the varying levels of haematocrit seen in diabetic outpatients, also affect the accuracy of One Touch Ultra.
Conclusion: The accuracy of SMBG meters can be affected by haematocrit as well as non-glucose sugars. The results pattern seen in the analytical assessment for haematocrit also occurs with real patient samples. In accurate meters increase the risk of mis-management of diabetes and new performance criteria for SMBG meters need to take this into account.
MeterMethod correlationHct
(22%)
HCT
(62%)
Maltose
(5.6 mmol/L)
Galactose
(5.6 mmol/L)
Xylose
(5.6 mmol/L)
NovaMax Plus8.5%9.3%5.8%6.8%6.7%7.8%
Glucofix mio Plus7.8%3.8%5.8%11.5%9.1%6.4%
Glucomen Lx Plus7.2%7.1%4.1%8.3%10.4%4.7%
AccuChek Aviva9.5%20.2%13.4%20.2%68.0%15.4%
Ascencia Breeze 29.5%31.6%32.7%19.8%13.0%9.3%
Optium Xceed15.5%28.9%46.8%14.7%11.5%13.6%
One Touch Ultra16.6%42.9%43.0%17.0%21.9%16.3%
Supported By: Nova Biomedical