A CLINICAL LABORATORY ASSESSMENT OF SIGMA METRICS OF FREQUENTLY ASSAYED BIOCHEMICAL PARAMETERS

Abstract

Background: The focus of the Six Sigma quality management methodology is on finding and eliminating
errors to raise operational quality. The use of Six Sigma in laboratory procedures makes it possible to identify
errors and use cutting-edge ways to save costs without compromising quality. In order to analyse the study
biochemical laboratory’s performance and to design and choose the best strategy for enhancing the
performance of problematic analytes, the laboratory set out to assess the process performance of commonly
examined parameters on a sigma scale. Methods: Retrospective data collection for quality control was
conducted between June and September 2022. Sigma metrics were derived using “Total Allowable Error
(TEa),” “Coefficient of Variation (CV),” and “Average Bias” for six biochemical parameters measured on the
Analyser following the Clinical Laboratories Improvement Act (CLIA). To determine the root of the fault, the
Quality Goal Index(QGI) of the problematic analytes were generated. Results: The first three of the following
parameters—cholesterol, amylase, HDL, triglycerides, SGOT, and SGPT—produced good sigma values,
while triglycerides, SGOT, and SGPT fared badly. Finally, the Quality Goal index was determined for the
parameters if the issue is brought on by imprecision, inaccuracy, or both. Conclusion: The study’s
conclusions indicate that sigma metrics is a useful tool for assessing the analytical performance of a clinical
biochemistry laboratory and that strong internal Quality Control (IQC) requirements are not required for
parameters with Sigma between 3-6. However, prior to routine usage, root cause investigation and technique
performance improvement should be carried out for a problem analyte with a sigma metric below 3.