ANALYTICAL PERFORMANCE EVALUATION OF HEMATOLOGICAL PARAMETERS USING SIGMA METRICS BASED ON DIFFERENT TOTAL ALLOWABLE ERROR
Main Article Content
Abstract
Objective: To evaluate the analytical performance of four hematological parameters—white blood cell count (WBC), red blood cell count (RBC), hemoglobin concentration (HGB), and platelet count (PLT)—measured on the DxH900 analyzer using Sigma metrics calculated based on different sources of allowable total error (TEa).
Methods: A cross-sectional descriptive study was conducted at the Department of Hematology and Blood Transfusion, Hanoi Medical University Hospital, from July 2025 to December 2025.
Materials: Beckman Coulter internal quality control (IQC) materials at three concentration levels and external quality assessment (EQA) samples from the External Quality Assessment Program of the Center for Quality Control in Medical Laboratory, Hanoi Medical University.
Study subjects: Sigma metrics of four hematological parameters (WBC, RBC, HGB, and PLT) measured on the DxH900 analyzer were evaluated using different TEa specifications, including CLIA, Rilibäk, SOTA, EFLM 2022, and MIN SPANHI EQA.
Main findings: The Sigma performance of the hematological parameters varied considerably depending on the TEa specification applied. Using TEa criteria from CLIA, EFLM 2022, and Rilibäk, approximately 66.7%–78% of the parameters achieved an “Excellent” quality level (Sigma > 6). This proportion decreased to 33.3% when more stringent TEa specifications, such as SOTA and MIN SPANHI EQA, were applied. PLT consistently demonstrated the highest and most stable Sigma performance across different TEa specifications, whereas HGB was the parameter most affected by changes in TEa criteria.
Conclusion: The analytical performance of WBC, RBC, HGB, and PLT on the DxH900 system and their Sigma-based quality classifications varied substantially according to the TEa source applied. Therefore, laboratories should select an appropriate and consistent TEa source when evaluating analytical performance using Sigma metrics.
Keywords
Sigma metrics, Six Sigma, Hematology, Total allowable error (TEa), Quality management, DxH900
Article Details
References
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