Six Sigma Approach for Performance Analysis of Hematology Analyzers in a Clinical Laboratory

Background: Accurate laboratory results are crucial for patient care, necessitating rigorous performance monitoring.Sigma metrics, a statistical method, can be used for performance evaluation of analytical methods in a diagnostic laboratory.Objective: This study aimed to evaluate performance and recommend customized quality control design for an automated blood count analyzer by application of Six sigma methodology.Methods: Internal Quality control and peer group evaluation data were used to calculate average imprecision and bias observed for the analytical instrument under study.CLIA (Clinical Laboratory Improvement Amendments) goals for analytical performance (Total allowable error) were applied to derive the 'sigma value' for the key measured parameters-Hemoglobin (Hb), Red Blood Cell count (RBC), Hematocrit (HCT), White Blood Cell count (WBC) and Platelet count to rate the performance based upon sigma scale and recommend tailored quality control strategies for each parameter. Results:The analyzer showed acceptable performance (above 3 sigma) for all parameters evaluated, with some parameters like Platelets showing beyond world class performance.While the overall analyzer performance was observed to be acceptable, a potential for further optimization was realized, especially for parameters like RBC and Hematocrit. Conclusion:Six sigma is an invaluable statistical tool available to diagnostic laboratories to ascertain analytical performances of its testing methods and optimize quality control processes, by utilizing readily available internal and external quality assurance data.