全血细胞计数室间质量评价结果分析及西格玛性能验证

An Analysis of Quality Evaluation Results and Performance Verification of Sigma in the Complete Blood Cell Count

目的回顾性分析2014年至2018年全国全血细胞计数室间质量评价结果及西格玛管理在质量改进中的应用。方法以实验室参加全国全血细胞计数室间质量评价回报结果为研究对象,将实验室的室内质控在控数据的累计变异系数作为不精密度的估计值,用实验室参加室间质评的测定值与靶值的百分差值的绝对值的平均值作为实验室检测的偏倚估计值,根据卫生行业标准WS/T 406-2012中的相关要求,计算相应项目的西格玛(σ)值,并绘制标准的西格玛性能验证图。结果从2014年至2018年参加全国全血细胞计数室间质量评价PT得分来看,2014年和2016年成绩较好,PT平均得分均为100%,2015年成绩最差,PT平均得分仅有62.5%。在全血细胞计数的8个项目中,质量评价成绩比较满意的是WBC、RBC、HGB、PLT、MCH等,PT得分均为100%。成绩不稳定的项目是MCV及其关联项目HCT和MCHC,PT得分为0~100%不等。整体来看,2014年至2018年全血细胞计数室间质评项目的变异系数逐渐变小,总体趋势是σ水平逐步提高,σ<3的项目逐步减少,σ≥3的项目比例逐步提高。2014年和2016年的全血细胞计数室间质评PT评分均为100%,但2014年和2016年σ≥3的项目比例分别只有12.5%(2/16)和56.25%(9/16)。2015年σ≥3的项目比例为50%(4/8),高于2014年的12.5%(2/16)。2017年至2018年PT成绩比2015年有明显提高,但仍有31.25%(5/16)和18.75%(3/16)的项目的σ<3,虽然实验室的精密度(CV值)比2014年明显改善,但项目的PT得分只有93.75%~95.00%。结论PT成绩满意,σ水平不一定高,要提高检验项目的σ水平,应关注实验室的精密度和准确度,西格玛性能验证比单独的能力验证更能客观评价实验室的检测能力。

Objective To conduct a retrospective analysis of the quality evaluation results of the national complete blood cell count from 2014 to 2018,and to discuss the application of Sigma management in quality improvement.Methods Taking the results of the laboratory’s participation in the evaluation of the quality of the complete blood cell count as the research object,the cumulative coefficient of variation of the laboratory’s internal quality control in the control data was used as an estimate of the degree of non-precision,and the absolute value of the percentage difference between the measured value of the laboratory’s participation in the external quality assessment and the target value.As an estimate of bias for laboratory testing,theσvalue of the corresponding item was calculated according to the relevant requirements of the health industry standard WS/T 406-2012,and the standard Sigma performance verification plot was drawn.Results Using results of 2014 to 2018 to participate in the national complete blood cell count quality evaluation PT score,performances of 2014 and 2016 were better,in which PT average score was 100%,while 2015 results were the worst,in which PT average score was only 62.5%.Among the 8 items of complete blood cell count,the quality evaluation score was more satisfied with WBC,RBC,HGB,PLT,MCH,etc.,and the PT score was 100%.Projects with unstable grades were MCV and its associated projects HCT and MCHC,with PT scores from 0 to 100%.Overall,the coefficient of variation of the complete blood cell count interstate evaluation project gradually decreased during 2014-2018,and the overall trend showed that theσlevel gradually increased,theσ<3 project decreased gradually,and the proportion ofσ≥3 items gradually increased.In 2014 and 2016,the complete blood cell count PT scores was 100%,but in 2014 and 2016σ≥3 project proportion was only 12.5%(2/16)and 56.25%(9/16),respectively.Theσ≥3 of projects was 50%(4/8)in 2015,higher than 12.5%(2/16)in 2014.PT scores during 2017-2018 were significantly higher than in 2015,but there were still 31.25%(5/16)and 18.75%(3/16)projectsσ<3,although the laboratory precision(CV value)improved significantly from 2014,but the project PT score was only 93.75 to 95%.Conclusion PT results are satisfactory,but theσis not necessarily high.In order to improve theσlevel of inspection projects,we should pay more attention to the precision and accuracy of the laboratory.Sigma performance verification,compared with individual capability verification,can objectively evaluate the laboratory’s testing capabilities.