Evaluation of measurement uncertainty in clinical chemistry assays based on the data of internal quality control and external quality assessment / 中华检验医学杂志

ABSTRACT

ObjectiveTo evaluate the suitability of Nordtest guideline in estimating measurement uncertainty of routine tests in clinical laboratory.MethodsData of clinical laboratory of Beijing Tongren Hospital were collected,which came from 176 days of Internal Quality Control ( IQC ) from July 2010 to December 2010 and 6 times of External Quality Assesment ( EQA ) of NCCL from 2009 to 2010.The combined and expanded uncertainties of 21meaurements (sodium, potassium, chlorine,calcium,phosphrous,glucose,urea nitrogen,creatinine,uric acid,total protein,albumin,total bilirubin,direct bilirubin, alanineaminotransferase, aspartateaminotransferase, alkalinephosphatase, lactate dehydrogenase,glutamyl transpeptidase,creatine kinase,triglyceride and total cholesterol) were evaluated according to Nordtest guideline.ResultsOf all the measurements,expanded uncertainty of direct bilirubin ( 17.69％ ) was the highest.For some enzymes such as ALT,AST,ALP and LDH,expanded uncertainties were all over 10％ markedly influenced by the calibrator uncertainty.Expanded uncertainty of triglyceride was 12.7％,also largely influenced by calibrator uncertainty,while that of total cholesterol was 6.96％.ConclusionsNordtest guideline is suitable to evaluate the measurement uncertainty of routine assays in clinical laboratory.However,calibrator uncertainty should be taken into account in the process of evaluation.