Abstract
External quality assessment (EQA) including extensive participants often result in abnormal distribution. Robust statistical methods are insensitive to slight deviation for a given probability model and can estimate the population parameters utilizing robust algorithm. The aim of this study was to evaluate the blood glucose testing performance of EQA in China using ISO 13528 robust statistical method. A total of 4571 participants measured two lots of materials at different concentrations and submitted the results through the Clinet-EQA reporting system V1.5. Data were collected and analyzed by Clinet-EQA evaluating system and SPSS 13.0. Participants were classified by method principles they adopted. Acceptability of relative differences between each result and robust mean of the group was calculated using biological variation desirable quality specification for allowable total error. The kernel density plots and Youden Plot were also applied to show the distribution of z-scores. The robust means of the two lots were 6.31 mmol/L and 15.71 mmol/L, and the robust standard deviations were 0.23 mmol/L and 0.5 mmol/L, respectively. Acceptability of relative differences was more than 90 % among all groups. About 91.5% and 89.7 % of the participants out of the two lots fulfilled the condition of |z| ≤ 2. In addition, 87.2 % participants fell inside the confidence ellipse for probability levels of 95 % in Youden Plot. According to the statistical results, we can conclude that most participants are qualified for performing blood glucose test and ISO 13528 robust statistical method is appropriate for EQA result analysis.
References
Manser MM, Chatterton J, Francis J, Guy E, Holliman R, Ho-Yen D, Johnson J, Chiodini PL (2010) The United Kingdom National External Quality Assessment Service for parasitology: toxoplasma serology scheme. J Clin Pathol 63:1112–1115
Hastings RJ, Maher EJ, Quellhorst-Pawley B, Howell RT (2008) An internet-based external quality assessment in cytogenetics that audits a laboratory’s analytical and interpretative performance. Eur J Hum Genet 16:1217–1224
Kang FF, Wang W, Zhang CB, Wang ZG (2013) Establishment of an assigned value and its uncertainty for tumour markers in proficiency testing in China. Accred Qual Assur 18:435–439
ISO 13528 (2005) Statistical methods for use in proficiency testing by inter-laboratory comparisons
Desirable specifications for total error, imprecision, and bias, derived from intra- and inter-individual biologic variation (2014) http://www.westgard.com/biodatabase1.htm. Accessed 12 May 2014
Hwang IS, Lee SR, Cho S, Chae KR, Park HJ, Lee JH, Heo OS, Hong SY, Kim WS (2014) Evaluation of proficiency tests in microbiological analysis: enumeration of aerobic microorganisms. Accred Qual Assur 19:41–46
Fraser CG, Petersen HP (1999) Analytical performance characteristics should be judged against objective quality specifications. Clin Chem 45:321–323
Skitek M (2005) Acceptability limits based on biology goals in haematology EQAS. Accred Qual Assur 10:112–115
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Xiao, Y.L., Zhang, C.B., Zhao, H.J. et al. Application of ISO 13528 robust statistical method for external quality assessment of blood glucose measurements in China. Accred Qual Assur 19, 397–401 (2014). https://doi.org/10.1007/s00769-014-1078-z
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DOI: https://doi.org/10.1007/s00769-014-1078-z