Sigma metrics for assessing the analytical performance of 14 biochemical analytes in Mansoura university children’s hospital laboratories (MUCHLs) using CLIA LIMITS 1988 & 2024

Abstract

Introduction

Analytical quality is a crucial prerequisite for best practice in medical laboratory. Six-Sigma Methodology (SM) is a quality measurement tool used to evaluate laboratory performance. This study aims to assess the analytical phase baseline performance using SM and compare results using TEa of CLIA 1988 and CLIA 2024.

Materials and methods

Coefficient of variation and bias were determined for 14 analytes. The sigma level for each parameter was calculated using total allowable error (TEa) for CLIA 1988 and CLIA 2024. The quality goal index ratio was calculated for analytes with Sigma less than 3. Normalized method decision Charts were plotted for level 1 and 2 Bio-Rad internal quality control for both CLIA 1988 and 2024.

Results

Using CLIA TEa 1988, HDL-C, triglycerides & uric acid for level 1 and ALT, AST, HDL-C, calcium, triglycerides & uric acid for level 2 had six Sigma world class performance, meanwhile, only BUN for level 1 and 2 performed less than 3. Using CLIA TEa 2024, HDL-C, GGT, and triglycerides for level 1 and ALT, AST, calcium, GGT, and triglycerides for level 2 had world class quality performance. Meanwhile, creatinine, glucose, BUN for level 1 and BUN and creatinine for level 2 performed less than 3.

Conclusion

Evaluation of baseline analytical performance using SM revealed lower sigma values with stringent CLIA TEa 2024 versus tolerant CLIA TEa 1988. Improvement in the methodology of analytes with poor performance on some assay platforms with stringent quality control regimes is recommended.