ABSTRACT
Objective To evaluate reference intervals consistency of 18 routine biochemistry among mutual recognition labora-tories by analyzing the information of reference intervals of these laboratories in Beijing-Tianjing-Hebei region.Methods Laboratories submitted the data of reference intervals via interval quality assessment(EQA)software which was based on WEB,then the background of the software save the data as Microsoft Excel 2007 document.Finally,the mutual recognition routine biochemical projects,including Kalium(K),Sodium(Na),Chlorinum(Cl),Calcium(Ca),Phosphorus(P),Total protein(TP),Albumin(ALB),Total cholesterol(TC),Triglyceride(TG),Creatinine(CRE),Urea(URE),Uric acid (UA),Glucose(GLU),Alanine amino transaminase(ALT),Aspartate aminotransferase(AST),γ-glutamyltranspeptidase (GGT),Lactate dehydrogenase(LDH)and Creatine kinase(CK)of 56 mutual recognition laboratories were chosen,and perform analysis on upper and lower limits of reference intervals and their sources.Results The sources of reference inter-vals differ among different laboratories.As for projects owning hygiene professional standards(including K,Na,Cl,Ca,P, TP,ALB,CRE,URE,ALT,AST,GGT,LDH,CK),the primary sources were hygiene professional standards(23.1%~48.1%),manufacturer instructions of reagents/instrument(17.3%~41.8%)and National Clinical Laboratory Procedures (18.9% ~37.0%),as for projects which didn't have professional standards(including TC,TG,UA and GLU),the main sources were manufacturer instructions of reagents/instrument(>41.1%)and National Clinical Laboratory Procedures(>45.3%).Moreover,more than half of laboratories(50.9%~58.9%)had verified the reference intervals.There were little difference among laboratories in the upper and lower limits of Cl,Ca,P,K and GLU,but bigger difference for other projects. Conclusion The upper and lower limits of reference intervals werenot consistent among laboratories.In order to ensure the comparability of the test results in beijing-tianjin-hebei region,laboratories should use reference intervals based on the popu-lation of beijing-tianjin-hebei region or China.
ABSTRACT
Important objectives of external quality assessment (EQA) is to detect analytical errors and urge laboratories to take corresponding corrective actions.The paper described knowledge required to interpret EQA results and present a structured approach on how to handle unacceptable EQA results.The interpretation of EQA results depends on five key points:the control material,the target value,the number of replicates,the acceptance limits and between lot variations in reagents.When there are unacceptable EQA results,these factors may be the sources of errors.The ideal EQA sample has two important properties:having no matrix effects;having a target value established with a reference method.If either of these two criteria is not entirely fulfilled,results not related to the performance of the laboratory may arise.To help and guide the laboratories in handling an unacceptable EQA result,National Center for Clinical Laboratories has developed a preliminary investigation on the sources of errors and corrective actions for nonconforming EQA results in fifteen EQA schemes.Then a flow chart with additional comments was developed based on the investigation and the document of QMS24 to help laboratories improve quality by use of EQA results.
ABSTRACT
Objective To investigate the reasons of unacceptable results and corrective measures adopted in external quality assessment (EQA)for blood gas and acid-base analysis.Methods The reasons of unacceptable results and corrective measures for three EQA testing events of blood gas and acid-base analysis in 2016 were reported through EQA system based on web which was developed by National Central for Clinical Laboratories.The responses were divided into seven major groups,including EQA samples,errors in reporting results,methodology,equipments,techniques,EQA evaluations and unexplainable results after survey.Results The disqualified rates of EQA survey on blood gas and acid-base analysis were ranged from 0.5％ to 13.1％ and reporting rates of disqualification causes were ranged from 45.8％ to 69.0％ (except for the groups less than 20 laboratories).In the reasons for unacceptable results technological defects (35.9％ to 37.0％)were mainly associated with inappropriate specimen handling and/or storing,reagents and calibration problems.The defects of equipments (24.4％ to 27.9％) included mainly the malfunction and failure to adhere to scheduled instrument maintenance procedures.The errors in reporting results (12.2％ to 19.7％) were mostly transcription errors and reporting wrong codes.The unexplainable results after survey account for 8.7％ to 9.6％.The methodological defects (8.1％ to 11.8％) were largely attributed to inadequate training and quality control method.The defects of EQA evaluations (0.8％ to 3.3％)were all due to inappropriate grouping.The categorizations of the problems in the three EQA testing events were similar.The most corrective measures were appropriate,in which re-education and training for staff and improvement in instruments,reagents,internal quality control,calibration and process of reporting results were included.Conclusion The analysis and classification for reasons of unacceptable EQA results should be helpful for laboratories in identifying opportunities for improvement and adopting corrective measures in time.