Pragmatic Approach of Verification of Examination Procedures in Clinical Laboratory for Imprecision,Trueness and Diagnostic Accuracy / 现代检验医学杂志

Objective To propose a practice model for implementing procedures employed for the verification of validated ex-amination procedures already used for at least 2 years in their laboratory,in agreement with the ISO 15189 requirement at the Section 5.5.1.2.Methods In order to identify the operative procedure to be used,approved documents were identified, together with the definition of performance characteristics to be evaluated for the different methods;the examination proce-dures used in laboratory were analyzed and checked for performance specifications reported by manufacturers.Then,opera-tive flow charts were identified to compare the laboratory performance characteristics with those declared by manufacturers. Results The choice of performance characteristics for verification was based on approved documents used as guidance,and the specific purpose tests undertaken,a consideration being made of:imprecision and trueness for quantitative methods;diag-nostic accuracy for qualitative methods;imprecision together with diagnostic accuracy for semi-quantitative methods.Conclu-sion The described approach,balancing technological possibilities,risks and costs and assuring the compliance of the funda-mental component of result accuracy,appears promising as an easily applicable and flexible procedure helping laboratories to comply with the ISO 15189 requirements.

Analysis of Reference Intervals of 18 Routine Biochemistry in 56 Mutual Recognition Laboratories in Beijing-Tianjing-Hebei Region / 现代检验医学杂志

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.

Quality Requirements for Reference Intervals and Decision Limits in Clinical Laboratory / 现代检验医学杂志

Reference intervals and decision limits are critical parts of the clinical laboratory report.The evaluation ot their correct use represents a tool to verify the post analytical quality.Four elements are identified as indicators:① The use of decision limits for lipids and glycated hemoglobin.② The use of common reference values.③The presence of gender-related reference intervals for at least the following common serum measurands (besides obviously the fertility relate hormones):alkaline phosphatase (ALP),alanine aminotransferase (ALT),creatine kinase (CK),creatinine,gamma-glutamyl transferase (GGT),IgM,ferritin,iron,transferrin,urate,red blood cells (RBC),hemoglobin (Hb) and hematocrit (HCT).④) The presence of age-related reference intervals.The problem of specific reference intervals for elderly people is discussed,but their use is not recommended.On the contrary it is necessary the presence of pediatric age-related reference intervals at least for the following common serum measurands:ALP,amylase,creatinine,inorganic phosphate,lactate dehydrogenase,aspartate aminotransferase,urate,insulin like growth factor 1,white blood cells,RBC,Hb,HCT,alfafetoprotein and fertility related hormones.The lack of such reference intervals may imply significant risks for the patients.

Interpretation of External Quality Assessment Results in Clinical Laboratories and Suggested Approach on Investigating Unacceptable Results / 现代检验医学杂志

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.

Investigation on reasons of unacceptable external quality assessment results for blood gas and acid-base analysis in China / 临床检验杂志

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.

Study on the probability of hepatitis B virus infection at public service places / 中华流行病学杂志

Objective To provide data for the control and prevention of hepatitis B and HBV surface antigen(HBsAg)status among the appliances and practitioners working in the public service places.Methods 63 beauty parlors,barber shops and bathing centers selected under stratified randomization sampling method and 682 workers were investigated through questionnaire.HBsAg from the appliances of the public service places and employee was detected by RIA.Results Two main sanitizing modes that including alcohol cleaning(34.60%)and ultraviolet light disinfection(30.79%)were used.The rates of testing on HBsAg among the appliances were 2.13% at the public service places,and were 0.63%,2.67% and 3.70% in large-.medium-and small-sized appliances respectively.The rate of testing on HBsAg on large-,medium-and small-sized appliances were statistically different(χ2=6.68,P＜0.05).The positive rates of HBsAg on the appliances of beauty parlors,barbering shops and footbath inns were 2.97%,0.61% and 3.42% respectively.People working in different service sites had different rates of HBsAg:those who worked at the‘acne needle'and the forceps were 5.13% and 4.17%.The positive rate of HBsAg among the workers in the public service places was 7.13%.The rates of HBsAg among the workers in large-,medium-and small-sized public service places were 7.34%,8.33% and 2.94% respectively.The rates of HBsAg among the workers in beauty parlors,barbering shops,footbath inns and bathing centers were 9.01%,6.37%,4.35% and 7.29% respectively.HBsAg positive rates were different among the workers working at different service sites:13.33% at tattoo business.12.68% in pedicures workers and 8.03% in massagists.Conclusion It is important to improve the sanitizing management of the appliances used in the public service places and to improve the knowledge,attitude,as well as practice of vaccination on hepatitis B among those populations.