Fast and reliable ethanol assays analysis are used in a clinical context for patients suspected of ethanol intoxication. Mostly, automated systems using an enzymatic reaction based on ethanol dehydrogenase are used. The manuscript focusses on the evaluation of the performance of these assays.
Data included 30 serum samples used in the Belgian EQA scheme from 2019 to 2021 and concentrations ranged from 0.13 to 3.70 g/L. A regression line between target concentrations and reported values was calculated to evaluate outliers, bias, variability and measurement uncertainty.
A total of 1,611 results were taken into account. Bias was the highest for Alinity c over the whole concentration range and the lowest for Vitros for low concentrations and Cobas 8000 using the c702 module for high concentrations. The Architect and Cobas c501/c502 systems showed the lowest variability over the whole concentration range. Highest variability was observed for Cobas 8000 using the 702 module, Thermo Scientific and Alinity c. Cobas 8000 using the c702 module showed the highest measurement uncertainty for lower concentrations. For higher concentrations, Alinity c, Thermo Scientific and Vitros were the methods with the highest measurement uncertainty.
The bias of the enzymatic techniques is nearly negligible for all methods except Alinity c. Variability differs strongly between measurement procedures. This study shows that the Alinity c has a worse measurement uncertainty than other systems for concentrations above 0.5 g/L. Overall, we found the differences in measurement uncertainty to be mainly influenced by the differences in variability.
Research funding: None declared.
Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
Competing interests: Authors state no conflict of interest.
Informed consent: Not applicable.
Ethical approval: Not applicable.
1. Ishmayana, S, Fadhlillah, M, Kristia, Y, Budiman, H. Validation of a modified alcohol dehydrogenase assay for ethanol determination. Curr Chem Lett 2015;4:77–84. https://doi.org/10.5267/j.ccl.2015.1.001.Search in Google Scholar
3. Krasowski, MD, Wilcoxon, RM, Miron, J. A retrospective analysis of glycol and toxic alcohol ingestion: utility of anion and osmolal gaps. BMC Clin Pathol 2012;12:1. https://doi.org/10.1186/1472-6890-12-1.Search in Google Scholar PubMed PubMed Central
4. Karch, SB. Drug abuse handbook. Boca Raton, FL, USA: CRC Press; 2019:1156 p.Search in Google Scholar
5. Handbook for calculation of measurement uncertainty in environmental laboratories (NT TR 537 - Edition 4). [Internet]. Nordtest; 2017. Available from: https://www.nordtest.info/wp/2017/11/29/handbook-for-calculation-of-measurement-uncertainty-in-environmental-laboratories-nt-tr-537-edition-4/ [Accessed 17 Jan 2022].Search in Google Scholar
6. Coucke, W, Tanasković, JV, Bouacida, L, Broeders, S, China, B, Demarteau, M, et al.. Alternative sample-homogeneity test for quantitative and qualitative proficiency testing schemes. Anal Chem 2019;91:1847–54. https://doi.org/10.1021/acs.analchem.8b03313.Search in Google Scholar PubMed
7. Coucke, W, Blerk, MV, Libeer, J-C, Campenhout, CV, Albert, A. A new statistical method for evaluating long-term analytical performance of laboratories applied to an external quality assessment scheme for flow cytometry. Clin Chem Lab Med 2010;48:645–50. https://doi.org/10.1515/CCLM.2010.122.Search in Google Scholar PubMed
8. Pinheiro, J, Bates, D. Mixed-effects models in S and S-PLUS. New York, USA: Springer Science & Business Media; 2006.Search in Google Scholar
9. Coucke, W, Charlier, C, Lambert, W, Martens, F, Neels, H, Tytgat, J, et al.. Application of the characteristic function to evaluate and compare analytical variability in an external quality assessment scheme for serum ethanol. Clin Chem 2015;61:948–54. https://doi.org/10.1373/clinchem.2015.240176.Search in Google Scholar PubMed
11. Dubois, N, Sqalli, G, Gilson, M, Charlier, C. Analytical validation of a quantitative method for therapeutic drug monitoring on the Alinity®c Abbott. Ann Biol Clin 2020;78:147–55. https://doi.org/10.1684/abc.2020.1535.Search in Google Scholar PubMed
12. Krintus, M, Fernandez, JA, Chesters, C, Colla, R, Ford, C, Frattolillo, D, et al.. Analytical performance of 10 high-volume clinical chemistry assays on the alinity c system. Lab Med 2019;50:e1–8. https://doi.org/10.1093/labmed/lmy053.Search in Google Scholar PubMed
The online version of this article offers supplementary material (https://doi.org/10.1515/cclm-2022-0285).
© 2022 Walter de Gruyter GmbH, Berlin/Boston