B-071 Sigma Metrics Performance Assessment of VITROS Systems in the Emergency Clinical Chemical Laboratory

Background The efficiency and accuracy of the clinical laboratory is critical for patients’ diagnosis and treatment. Sigma metrics, combining with observed accuracy, precision, and total allowable error (TEa) into a single metric, is a useful way to measure detection quality. Sigma metrics is typically scored from 0 to 6 (the higher the score, the better the performance of the process). We noticed that many investigations on this tool are performed on different laboratories’ systems to derive peer median. In this study, we use Sigma metrics to assessed the perform of the Vitros® 5600 and 4600 liner automation in our emergency laboratory. In China, VITROS dry biochemistry has 26 CFDA approved dry chemical assays. According to «Chinese expert consensus on emergency laboratory capacity building and standardization», these assays are routinely sufficient for emergency. We routinely run 24 assays for our emergency patients. Methods Quality control (QC) data were collected for Vitros® 5600 and 4600 liner automation in the study time range (January to December 2024). Each assay has approximately 640 QCs (dataset included VITROS 5600 and 4600). Extremely QC outliers are ruled out based on Chanwennt criterion. Sigma metrics were then derived for each set of QC data from two analyzers, reagent lots, and calibration curves using the following equation: Sigma metric = (TEa - %Bias) / %CV TEa (Total Error Allowance): determined according to the industry standard of the National Health Commission of China, «Analytical Quality Standards for routine assays in Clinical Chemistry». %Bias (bias): obtained from national dry chemistry EQA program in 2024. %CV (coefficient of variation): obtained from our emergency laboratory internal quality control dataset in 2024. Results Analysis of the QC data for 2024 resulted in the following key findings: 22 of the 24 assays, which means 91.7% assays are with high sigma levels world-class (6s) or excellent (5s) levels, indicating that the analytical performances are highly accurate and reliable, and could provide strong support for clinical diagnosis. Here serum albumin and chloride ion, two assays were with lower Sigma level (4.5s,4.1s). It indicated that there need some improvement actions. After laboratory situation analysis, we found that these lower performances were resulted from reagent lot switch and instrument periodic maintenance frequency. We will follow the correction effect in the following year using same Sigma metrics tool. Conclusion World-class (6s) or excellent (5s) performance were achieved in 91.7% of the Vitros® 5600 and 4600 clinical chemistry assays in our laboratory. This figure demonstrates that the Vitros system excels in emergency laboratory analysis, providing high quality clinical results, reducing the need for repeat testing, lowering operational costs, and improving overall laboratory efficiency. It could also provide valuable experience for other routine laboratories.