SIX SIGMA METRICS: INDICATOR OF QUALITY ASSURANCE FOR CLINICAL BIOCHEMSITRY

Introduction: In present scenario Quality is the important aspect of laboratory practices. Mostly internal and external quality control are utilized to maintain quality in laboratory. Quality assurance of laboratory services is the need of present time in health care which require Quality Planning, Quality Control (QC), Quality Assessment (QA) and Quality Improvement .

Aims & Objectives:

1.      To quantify the defects and errors in analytical phase of  laboratory testing by sigma metrics and to represent the calculated sigma value.

2.      Application of six sigma test in laboratory with the IQC and EQAS to maintain quality laboratory services.

Methodology: Study was conducted at Clinical Biochemistry Laboratory, GMC Akola. We run IQC samples on daily basis and EQAS samples are running on monthly basis. Retrospectively we utilized data of IQC and EQAS from January to October 2023 for 16 Biochemical  Analytes. Sigma metrics for each parameter was calculated.

Result: The sigma metrics for IQC indicated that 1 out of 16 analytes qualified six sigma quality performance. Of these 15 analytes performance with sigma metrics was beteween three and six. We found different sigma value like more than6 for only HDL cholesterol and more than 3 for Amylase, Total Bilirunbin, Creatinine, Cholesterol, Glucose, Phosphorus, total Protein , SGPT , TG, UA, Urea, SGOT, which is among the acceptable range of performance.

Conclusion: In our study sigma value was highest for HDL cholesterol and other 15 analytes show sigma value between 3 to 6 which is acceptable range.  Sigma analysis is a continuous procedure and by taking the help of method decision chart we can improve on decision on making in clinical chemistry laboratory regarding optimising QC procedure.

一、研究背景
当前，质量是实验室实践的核心要义。实验室通常采用内部质量控制（Internal Quality Control, IQC）与外部质量评估（External Quality Assessment, EQAS）来维持检测质量。当前医疗保健领域对实验室服务的质量保障存在迫切需求，该体系涵盖质量策划、质量控制（Quality Control, QC）、质量评估（Quality Assessment, QA）与质量改进四大模块。

二、研究目的
1. 采用西格玛度量（Sigma Metrics）量化实验室检测分析阶段的缺陷与误差，并呈现计算得到的西格玛数值；
2. 结合内部质量控制（IQC）与外部质量评估（EQAS），将六西格玛方法应用于实验室质量管理，以保障优质的实验室检测服务。

三、研究方法
本研究于阿科拉政府医学院临床生物化学实验室（GMC Akola Clinical Biochemistry Laboratory）开展。研究每日开展内部质量控制（IQC）样本检测，每月开展外部质量评估（EQAS）样本检测。本研究回顾性采用2023年1月至10月期间16项生化分析物的IQC与EQAS数据，并计算各检测项目的西格玛度量值。

四、研究结果
内部质量控制（IQC）的西格玛度量结果显示，16项分析物中仅有1项符合六西格玛质量性能标准；其余15项分析物的西格玛度量值处于3至6区间。本研究观测到不同的西格玛数值：仅高密度脂蛋白胆固醇（HDL Cholesterol）的西格玛值大于6；淀粉酶（Amylase）、总胆红素（Total Bilirubin）、肌酐（Creatinine）、胆固醇（Cholesterol）、葡萄糖（Glucose）、磷（Phosphorus）、总蛋白（Total Protein）、谷丙转氨酶（SGPT）、甘油三酯（TG）、尿酸（UA）、尿素（Urea）、谷草转氨酶（SGOT）的西格玛值均大于3，均处于可接受的性能范围内。

五、研究结论
本研究中，高密度脂蛋白胆固醇的西格玛值最高，其余15项分析物的西格玛值处于3至6的可接受区间。西格玛分析是一项持续迭代的流程，借助方法学决策图表，我们可优化临床化学实验室的质量控制（QC）流程决策，进而提升实验室质量管理水平。