Evaluation of Analytical Process Performance by Six Sigma Method

Purpose: Clinical laboratories are responsible for producing reliable, reproducible and accurate test results. Should establish quality in their test analysis and evaluate process performance. Six sigma is a quality management strategy that evaluation of processes. The aim of our study is to evaluate the analytical process performance of routine tests in our laboratory with six sigma method. Methods: Internal quality control (IQC) data of routine tests in our laboratory were obtained retrospectively. Mean, standard deviation and coefficient of variation (CV) values of the IQC data were calculated. Process sigma values were calculated using the formula “Total Allowable Error (TEa)%-Bias% /CV% “. TEa values were determined according to CLIA’88. Sigma value ≤3 low quality, between 3 and 6 good quality and ≥6 was recognized as world class quality. Results: The sigma levels of all the tests we evaluated were >3. Sigma levels of albumin, creatinine, LDL, urea, chloride, total cholesterol, HDL, sodium for IQC 1; albumin, urea, UIBC, chloride, creatinine, potassium, sodium and direct bilirubin for IQC2 were between 3–6. The sigma levels of ALP, ALT, AST, CK, CKMB, iron, UIBC, phosphorus, GGT, glucose, calcium, LDH, magnesium, potassium, total protein, triglyceride, uric acid, amylase, lipase, direct bilirubin, total bilirubin, CRP for IQC 1; ALP, ALT, AST, CK, CK-MB, iron, phosphorus, GGT, glucose, calcium, total cholesterol, HDL, LDL, LDH, magnesium, total protein, triglyceride, uric acid, amylase, lipase, total bilirubin, CRP tests for IQC 2 were ≥6. Conclusion: Six sigma methodology is an effective method for evaluating the analytical process performance of the laboratory. According to the results of our study, our laboratory performance is good or first class.