Application of Sigma Metrics for Evaluation and Improvement of Quality Control in the Clinical Chemistry Laboratory of Udon Thani Cancer Hospital

Abstract

Background: Currently, the Six Sigma metrics are utilized across various professions, including the medical field, where they have been effectively implemented. This approach has particularly proven beneficial in assessing the efficiency of laboratory processes. Objective: To evaluate the performance of biochemical parameters by calculating their sigma metrics of Udon Thani Cancer Hospital. Method: This is a retrospective data study covering six months (January to June 2024). Collected data from internal quality control (IQC) and external quality assessment (EQA) assessments of 26 parameters. Calculated the %CV from IQC and %Bias from EQAS. Sigma metrics were calculated from CV, percentage bias, and total allowable error for 26 parameters. Sigma metrics serve as a tool for quality control planning by selecting the appropriate rules for each parameter. Result: From the application of Sigma metrics in testing 26 items, it was found that 58% were at an excellent level (≥ 6-Sigma), including BUN, TP, TBIL, triglyceride, calcium, ALP, LDH, HDL, LDL, Mg, DBIL, LIP, phosphorus, CO2, and Chol. 8% are at an excellent level (≥5-Sigma), including glucose and amylase. 15% are at a good level (≥ 4-Sigma), including CRE, uric acid, AST, and ALB. Poor levels (< 4-sigma) include Na, K, Cl, ALT, and HbA1c (19%). Conclusion: The Cobas 6000 C501 automatic analyzer in the clinical chemistry laboratory of Udon Thani Cancer Hospital has an analysis efficiency with a high level of Sigma metrics, ranging from good to excellent. It is possible to plan appropriate quality control to monitor errors that are easy for personnel to perform, thereby reducing the workload. At the same time, actions should be taken to improve the performance of the analysis parameters with a value of < 3-sigma.