A Clinical Laboratory Assessment of Sigma Metrics of Frequently Assayed Biochemical Parameters

Main Article Content

Sonia Bisht, Ranjana, Swapnila Roy


Introduction: Six Sigma is a quality management method that emphasizes the detection and elimination of flaws in order to enhance the quality of operations. Six Sigma implementation in laboratory procedures enables mistake detection and the adoption of cutting-edge ways to cost reduction without compromising quality. With this in mind, the study biochemical laboratory set out to evaluate the process performance of frequently assessed parameters on a sigma scale, which would aid in evaluating the laboratory's performance and would allow for the development and selection of the best strategy for improving the performance of problem analytes.

Objectives: Recognize the value of Six Sigma and use it to calculate Sigma metrics for frequently measured biochemical parameters, improving laboratory quality control.

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 Analyser following Clinical Laboratories Improvement Act (CLIA). To determine the root of the fault, 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 Quality Goal index were determined for the parameters if the issue is brought on by imprecision, inaccuracy, or both.

Conclusion: According to the study's findings, sigma metrics are a valuable tool for evaluating the analytical performance of a clinical biochemistry laboratory, and for parameters with sigma between 3-6, strict internal Quality Control (IQC) guidelines are not necessary. 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.

Article Details