Ongoing standardized verification of the accuracy of blood glucose meters systems for self-monitoring post-launch is important clinically and helps confirm appropriate performance of subsequently released lots of strips.1 In addition, publication of such studies is increasingly becoming a component of informed comparative purchasing decisions. ISO 15197:2013,2 for which mandatory compliance is recommended for SMBG systems by 2016,3 has tighter accuracy requirements than ISO 15197:2003,4 and outlines current minimum accuracy standards necessary in Europe for CE marking.
In this study, a postmarketing evaluation of the CE-marked and FDA-approved TD-4277 SMBG system was performed in accordance with ISO 15197:2013 protocols and requirements. The TD 4277 system (TaiDioc Technology Corp, Taiwan, ROC) is supplied in the United Kingdom as the GlucoRx Nexus (GlucoRx Ltd., Surrey, England) and in Germany as the GlucoCheck XL (aktivmed GmbH, Rheine, Germany). Three GlucoCheck XL systems, 500 tests from 3 strip lots (TD13J901 BOF, TD13I901 BOF,TD13H201 BOF with expiry dates July, June and May 2015 respectively) were supplied by aktivmed GmbH, Germany, for the study that was conducted from December 10 to December 19, 2013, at the Institute of Diabetes “Gerhardt Katsch,” Karlsburg, Germany. Ethical approval for the study was obtained from the Ethics Committee of the University of Greifswald.
Ear lobe capillary blood samples were taken from 121 subjects for duplicate glucose determination using the GlucoCheck XL and the glucose oxidase based YSI2300 STAT PLUS (YSI Incorporated, Yellow Springs, Ohio, USA) plasma glucose reference method. Trueness and precision of the comparison assay were verified using a range of YSI bioanalytical standards and controls. Samples had hematocrit values between 20% and 60% and after examination of glucose concentration ranges using the YSI, 100 subjects were included in the analysis of accuracy.
Table 1 demonstrates performance in relation to the minimum accuracy requirements of ISO 15197:2013 where for each of the 3 lots of strips at least 95% of results must fall within ±15 mg/dl of the comparison measurement results at blood glucose concentrations <100 mg/dl and within ±15% at concentrations ≥100 mg/dl. The standard also requires that at least 99% of individual results fall within consensus error grid zones A and B (5) when clinical accuracy is evaluated with 3 test strip lots. The relative bias according to Bland and Altman (6) ranged from –5.43% to –4.00% and the mean absolute relative difference from 6.24% to 6.99%.
Table 1.
Analytical and Clinical Accuracy of the TD-4277 With 3 Lots of Strips.
| SMBG system |
ISO 15197:2013 criteria within ±15 mg/dl and ± 15% |
|||
|---|---|---|---|---|
| Meter | Strip lot | Individual lots | 3 lots combined | Within consensus error grid zones A and B |
| GlucoCheck XL TD-4277 | TD13J901-BOF | 192/200 (96%) | 584/600 (97.3%) | 600/600 (100%) |
| TD13I901-BOF | 198/200 (99%) | |||
| TD13H901-BOF | 194/200 (97%) | |||
Numbers and percentages of results within system accuracy limits of ISO 15197:2013.
In conclusion, this study demonstrates that the TD-4277 SMBG system fulfils and exceeds the minimum analytical and clinical accuracy requirement of ISO 15197:2013.
Acknowledgments
TaiDioc Technology Corp, aktivmed GmbH, and GlucoRx Ltd were permitted to review and comment on the manuscript, but final decision on content was retained by the authors.
Footnotes
Abbreviations: CE, Conformité Européene; ISO, International Organization for Standardization; SMBG, self-monitoring of blood glucose.
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: All authors are employees of the Institut für Diabetes, Karlsburg, Germany, which carries out studies evaluating blood glucose meter systems on behalf of various companies.
Funding: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by aktivmed GmbH Oldenburger Str 17, 48429 Rheine Germany.
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