Six Sigma-Based Quality Assessment of Biochemical Analytes: A Comparative Analysis of Clinical Laboratory Improvement Amendments 1988 and 2024 Standards

Comparative Sigma Analysis: CLIA'88 vs CLIA'24

DOI: https://doi.org/10.5937/jomb0-58564
Keywords: Six Sigma, quality tool, total allowable error, quality control,

Abstract


Background: Laboratories have a responsibility to produce accurate and reliable results to ensure patient safety and meet quality standards. Within the Six Sigma quality management framework, different approaches may emerge depending on the total allowable error (TEa) limits defined by various standards. This study aimed to compare analyte sigma levels using CLIA 1988 and CLIA 2024 criteria, determine appropriate quality control procedures based on Westgard multirules, and identify potential sources of error using the Quality Goal Index.

Methods: Sigma values for 17 biochemical analytes were calculated based on internal and external quality control data using the formula (TEa – bias)/CV. The Quality Goal Index (QGI) was determined using the formula bias/(1.5×CV). All analytes were evaluated at the Karabuk Public Health Laboratory between November 2024 and March 2025.

Results: Amylase (Levels 1 and 2), total bilirubin (Level 1), high-density lipoprotein cholesterol (Levels 1 and 2), creatine kinase (Levels 1 and 2), and lactate dehydrogenase (Levels 1 and 2) demonstrated world-class sigma performance according to both CLIA 1988 and CLIA 2024 standards. However, a decline in sigma values was observed when calculated using the more stringent CLIA 2024 limits.

Conclusions: The comparison of CLIA 1988 and CLIA 2024 standards demonstrated that stricter TEa limits can significantly impact sigma performance. While some analytes retained world-class performance, others showed a notable decline, requiring enhanced quality control measures. These findings emphasize the need for laboratories to periodically reassess test performance in light of evolving regulatory standards to ensure continued analytical reliability and patient safety.

Author Biographies

Mert Üğe, Karabuk Public Health Laboratory

Dr. Mert Üğe is a specialist in Medical Biochemistry currently working at a healthcare institution in Turkey. She graduated from Ege University Faculty of Medicine and completed his residency in Medical Biochemistry at İzmir Katip Çelebi University Atatürk Training and Research Hospital. Dr. Üğe has experience in pharmaceutical and toxicological research, with a particular focus on method validation using LC/MS systems for environmental pollutants such as bisphenol and phthalates. His thesis investigated the effects of these endocrine-disrupting chemicals in a specific patient population. He has contributed to several laboratory-based studies focusing on these contaminants and their health impacts.

 

In addition to her analytical expertise, Dr. Üğe has a keen interest in quality management systems within clinical laboratories. He actively participates in quality improvement initiatives and laboratory accreditation processes. Passionate about academia, he is also engaged in teaching and mentoring medical and biomedical students, with a strong dedication to advancing academic research and scientific education.

Prof. Dr. Saliha, Izmir Katip Celebi University Atatürk Training and Research Hospital

Prof. Dr. Saliha Aksun is a Professor of Medical Biochemistry at Izmir Katip Çelebi University. She works in the Department of Medical Biochemistry, where she is actively involved in academic instruction for both undergraduate students and medical residents. In addition to her teaching responsibilities, she oversees administrative operations in the university’s Drug and Toxicology Laboratory. Her professional interests include clinical laboratory quality management, biochemical diagnostics, and toxicological analysis.

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Published
2025/06/05
Issue
Vol. 44 No. 8 (2025): Journal of Medical Biochemistry
Section
Original paper

Copyright (c) 2025 Mert Üğe, Saliha Aksun

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