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Evaluation of Imprecision, Bias and Total Error of Clinical Chemistry Analysers

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Abstract

Context Two Biosystems analysers are used in our laboratory, a fully automated A25 and a semi-automated BTS-350. Internal quality control is done for both but external quality control only for A25. As BTS-350 is used for backup, it is important that the results of both analysers are not just comparable but also within predefined limits of systematic, random and total error (TE). Aim To evaluate the imprecision, bias and TE of the two Biosystem analysers. Materials and Methods Biosystems level-1 quality control sera lot number 70A was run in duplicate for 32 days on both the analysers. Between day imprecision (measured by the coefficient of variation), bias and TE were calculated for ten analytes and were checked to see whether they are within the acceptable minimum limits, desirable limits and optimum limits of allowable error based on specifications on Westgard’s website updated in 2014. Results On both the analysers, all the analytes except alkaline phosphatase were within the acceptable minimum limits of TE and most analytes were within the desirable limits of TE. Only TG on A25 was within the optimum limit of TE. Conclusion The two Biosystem analysers performed comparably with errors within acceptable limits for most analytes. BTS-350 was found to be a suitable and ready backup analyser for A25.

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References

  1. Ricos C, Perich C, Minchinela J, Álvarez V, Simón M, Biosca C, et al. Application of biological variation: a review. Biochem Med. 2009;19(3):250–9. doi:10.11613/BM.023.

    Article  Google Scholar 

  2. Bishop ML, Fody EP, Schoeff LE. Clinical chemistry. Principles, techniques, correlations. 7th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins; 2013.

    Google Scholar 

  3. Evaluating CD, Precision A. Clin Biochem Rev. 2008;29(Suppl 1):S23–6.

    Google Scholar 

  4. Johnson R. Assessment of bias with emphasis on method comparison. Clin Biochem Rev. 2008;29(Suppl 1):S37–42.

    PubMed Central  PubMed  Google Scholar 

  5. Clinical and Laboratory Standards Institute (2005) User verification of performance for precision and trueness; approved guideline. 2. Wayne, PA, USA: CLSI. CLSI document EP15-A2.

  6. White GH, Fraser I, AACB Uncertainty of Measurement Working Group. Uncertainty of measurement in quantitative medical testing: a laboratory implementation guide. Clin Biochem Rev. 2004;25(4):S1–24.

    CAS  PubMed Central  PubMed  Google Scholar 

  7. Fraser CG, Petersen PH, Ricos C, Haeckel R. Proposed quality specifications for the imprecision and inaccuracy of analytical systems for clinical chemistry. Eur J Clin Chem Clin Biochem. 1992;30(5):311–7.

    CAS  PubMed  Google Scholar 

  8. Ricos C, Alvarez V, Cava F, Garcia-Lario JV, Hernandez A, Jimenez CV, et al. Current databases on biological variation: pros, cons and progress. Scand J Clin Lab Invest. 1999;59(7):491–500.

    Article  CAS  PubMed  Google Scholar 

  9. Ricos C, Alvarez V, Cava F, Garcia-Lario JV, Hernandez A, Jimenez CV, Minchinela J, Perich C, Simon M (2014) Desirable specifications for total error, imprecision, and bias, derived from intra- and inter-individual biologic variation. http://www.westgard.com/biodatabase1.htm. Accessed May 2014.

  10. Ricos C, Alvarez V, Cava F, Garcia-Lario JV, Hernandez A, Jimenez CV, Minchinela J, Perich C, Simon M (2014) Minimum specifications for total error, imprecision, and bias, derived from intra- and inter-individual biologic variation. https://www.westgard.com/minimum-biodatabase1.htm. Accessed May 2014.

  11. Ricos C, Alvarez V, Cava F, Garcia-Lario JV, Hernandez A, Jimenez CV, Minchinela J, Perich C, Simon M (2014) Optimum specifications for total error, imprecision, and bias, derived from intra- and inter-individual biologic variation. http://www.westgard.com/optimal-biodatabase1htm.htm. Accessed May 2014.

  12. Barry PL (2014) QC: the Levey–Jennings control chart. http://www.westgard.com/lesson12.htm. Accessed May 2014.

  13. Oosterhuis WP. Gross overestimation of total allowable error based on biological variation. Clin Chem. 2011;57(9):1334–6.

    Article  CAS  PubMed  Google Scholar 

  14. Hackney JR, Cembrowski GS. Need for improved instrument and kit evaluations. Am J Clin Pathol. 1986;86(3):391–3.

    CAS  PubMed  Google Scholar 

  15. Coudène P, Marson B, Badiou S, Flavier S, Anelli S, Cristol JP, et al. Evaluation of the ABX Pentra 400: a newly available clinical chemistry analyser. Clin Chem Lab Med. 2005;43(7):782–92.

    Article  PubMed  Google Scholar 

  16. Miler M, Šimundić AM, Štefanović M, Ferenec-Ružić D, Kvaternik M, Topic E, Vrkic N. A model for results comparison on two different biochemistry analyzers in laboratory accredited according to the ISO 15189. Biochem Med. 2009;19(3):287–93. doi:10.11613/BM.2009.027.

    Article  Google Scholar 

  17. Plebani M. Laboratory errors: how to improve pre- and post-analytical phases? Biochem Med. 2007;17(1):5–9. doi:10.11613/BM.2007.001.

    Article  Google Scholar 

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Correspondence to S. S. Biswas.

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Biswas, S.S., Bindra, M., Jain, V. et al. Evaluation of Imprecision, Bias and Total Error of Clinical Chemistry Analysers. Ind J Clin Biochem 30, 104–108 (2015). https://doi.org/10.1007/s12291-014-0448-y

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  • DOI: https://doi.org/10.1007/s12291-014-0448-y

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