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Licensed Unlicensed Requires Authentication Published by De Gruyter June 8, 2022

Analytical performance of eight enzymatic assays for ethanol in serum evaluated by data from the Belgian external quality assessment scheme

Wim Coucke ORCID logo, Corinne Charlier, Kathleen Croes, Boris Mahieu, Hugo Neels, Christophe Stove ORCID logo, Jan Tytgat, André Vanescote, Alain G. Verstraete ORCID logo, Sarah Wille and Arnaud Capron



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.

Corresponding author: Dr. Wim Coucke, Quality of Laboratoreis, Sciensano, J. Wytsmanstraat 14 1050, Brussels, Belgium, E-mail:

  1. Research funding: None declared.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Competing interests: Authors state no conflict of interest.

  4. Informed consent: Not applicable.

  5. Ethical approval: Not applicable.


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Supplementary Material

The online version of this article offers supplementary material (

Received: 2022-03-23
Accepted: 2022-05-24
Published Online: 2022-06-08
Published in Print: 2022-07-26

© 2022 Walter de Gruyter GmbH, Berlin/Boston

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