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. 2019 May;13(3):514-521.
doi: 10.1177/1932296819841357. Epub 2019 Apr 11.

Laboratory Evaluation of Linearity, Repeatability, and Hematocrit Interference With an Internet-Enabled Blood Glucose Meter

Filiz Demircik  1   2 , Valeria Kirsch  1   3 , Sanja Ramljak  2 , Mario Vogg  4 , Anke H Pfützner  2 , Andreas Pfützner  1   2   4
Affiliations

Laboratory Evaluation of Linearity, Repeatability, and Hematocrit Interference With an Internet-Enabled Blood Glucose Meter

Filiz Demircik et al. J Diabetes Sci Technol. 2019 May.

Abstract

Background: In recent clinical trials, use of the MyGlucoHealth blood glucose meter (BGM) and electronic diary was associated with an unusual reporting pattern of glycemic data and hypoglycemic events. Therefore, the performance of representative BGMs used by the patients was investigated to assess repeatability, linearity, and hematocrit interference in accordance with regulatory guidelines.

Method: Ten devices and 6 strip lots were selected using standard randomization and repeatability procedures. Venous heparinized blood was drawn from healthy subjects, immediately aliquoted and adjusted to 5 target blood glucose (BG) ranges for the repeatability and 11 BG concentrations for the linearity tests. For the hematocrit interference test, each sample within 5 target BG ranges was split into 5 aliquots and adjusted to hematocrit levels across the acceptance range. YSI 2300 STAT Plus was used as the laboratory reference method in all experiments.

Results: Measurement repeatability or precision was acceptable across the target BG ranges for all devices and strip lots with coefficient of variation (CV) between 3.4-9.7% (mean: 5.7%). Linearity was shown by a correlation coefficient of .991; however, a positive bias was seen for BG <100 mg/dL (86% measurements did not meet ISO15197:2015 acceptance criteria). Significant hematocrit interference (up to 20%) was observed for BG >100 mg/dL (ISO15197:2015 acceptance criteria: ±10%), while the results were acceptable for BG <100 mg/dL.

Conclusions: The BGM met repeatability requirements but demonstrated a significant measurement bias in the low BG range. In addition, it failed the ISO15197:2015 criteria for hematocrit interference.

Keywords: blood glucose meter; hematocrit interference; linearity; repeatability.

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Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: This work was sponsored by a research grant from Novo Nordisk. AP has received research grants, travel support and consultancy fees from Novo Nordisk. AHP is the spouse of AP. All other authors have no conflict of interest.

Figures

Figure 1.
Figure 1.
Bland-Altman analysis for measurement of linearity across the entire data set. The range between the dotted lines represents ISO 15197:2015 acceptance criteria for clinical accuracy.
Figure 2.
Figure 2.
Hematocrit interference stratified by blood glucose concentration.
See this image and copyright information in PMC

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References

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