Z比分数评定法在大肠菌群能力验证评定中的应用

Application of Z-Ratio Score Evaluation Method in Verification and Evaluation of Coliform Group Ability

为了保证统计数据的合理性、准确性,本文采用Z比分数评定法对能力验证的数据进行分析。以总大肠菌群(多管发酵法)的能力验证数据为例,采用GB/T 28043—2019中的稳健技术(附录C稳健分析)统计方法,先计算中位数med(x),再计算中位绝对离差MADe(x),采用迭代算法A计算数据的稳健平均值c和稳健标准差b进而计算出能力评定标准差δ值,通过Z比分值法来评定各参加实验室能力,此方法可抵消不对称离群值分布带来的影响,提供了科学评价能力验证结果的手段。

In order to ensure the rationality and accuracy of the statistical data,the z-ratio score evaluation method is used to analyze the data of capability verification.Taking the data of total coliforms(multi-tube fermentation method)as an example,we used the robust technology(Appendix C robust analysis)statistical method in GB/T 28043—2019,calculate the median med(x)first,then calculate the median absolute deviation MADe(x),through the above two values,the robust averagec c,and the robust standard deviation b,could be calculated by algorithm A,thus we could obtain the ability evaluation standard deviationδ,each laboratory ability could be evaluated by the z-ratio score evaluation method finally.It can offset the impact of asymmetric outlier distribution,and provides a medium for evaluation of proficiency verification results scientifically and rationally.