Enhancing Laboratory Quality: A Comprehensive Sigma Metric Analysis for Diverse Biochemical Parameters

Ensuring quality in the analytical phase of clinical chemistry is paramount for accurate diagnosis and treatment. Sigma metrics offer a quantitative framework to assess and enhance laboratory performance. In this study, we intend to comprehensively assess diverse biochemical parameters using three different QC databases to determine their suitability and design a tailor-made QC plan based on this assessment.

This is a retrospective study, from an NABL-accredited laboratory. The coefficient of variation (CV) % was obtained from the IQC results and the Bias % from Proficiency Testing (PT) results. The Sigma value was calculated using the TEa from three different biological variation databases (EFLM database, Westgard database, CLIA database). QGI was calculated for parameters with a Sigma value <3.

Around 28-33 parameters in different instruments showed a Sigma value <3 (poor performance). However, several parameters lack TEa values in the CLIA database, preventing their inclusion in assessments of acceptability.

By integrating Sigma calculations with established TEa standards, this study helped in identifying areas needing improvement. This comprehensive assessment ensured the evaluation of the performance of diverse analytes, thereby ensuring higher accuracy and reliability in patient test results.