Analytical Performance Evaluation of Hematology Analyzer Using Various TEa Sources and Sigma Metrics

Abstract

Introduction: In clinical laboratory, the performance of the hematology analyzer should be checked routinely to ensure the desired quality. Therefore, the aim of the study was to assess the analytical performance of hematology analyzer using sigma metrics. Methods: The study included all daily internal quality control (IQC) data of hematology analyzer prospectively from August to October 2022. Data was collected using record formats by trained laboratory professionals. The sigma values of each CBC parameter were calculated using the formula: Sigma = (TEa – Bias) / CV. The TEa data were adopted from five different guidelines to calculate sigma value of the laboratory based on different specification. The bias of all complete blood count (CBC) parameters was calculated from the laboratory mean of the daily IQC data and the target value of the manufacturer in the insert kit. A coefficient of variations was also calculated using IQC data. Results: The current study found that sigma value of the analyzer varied based on source of TEa. Except HCT out 5 parameters included based on CLIA guideline, except MCV, MCHC, RDW, MPV and Basophil out of 15 parameters included based on EFLM 2022 minimum guideline, except Hb and PLT out of 9 parameters included based on SOTA guideline other parameters meets minimum specification (<3 sigma value). On the other hand, all parameters included in Rilibak and Standards of Spanish guideline achieved minimum specification (>3 sigma value). Conclusion: Sigma values of the CBC parameters have significantly varied depends on the TEa sources. So, it is recommended laboratory to use alternative sigma value based on its preference. Additionally, it is suggested that the laboratory to design local Westgard rules for each parameter based on sigma value.