The preparation and evaluation of human whole blood control materials for point-of-care glucose testing / 中华检验医学杂志

Objective:To prepare the control materials of point-of-care(POC) glucose testing and evaluate their homogeneity, stability and matrix effects.Methods:The high, medium and low concentration control materials were prepared from patient leftover whole blood, which was centrifuged, fixed, washed, filtered, and aliquoted. The homogeneity and stability of the control materials were evaluated according to CNAS (China National Accreditation Service for Conformity Assessment, CNAS) GL29:2010"Reference materials-General and statistical principles for certification". The control materials were used to evaluate the matrix effects in POC glucose detection systems by Deming regression, according to the Clinical and Laboratory Standards Institute (CLSI) EP14-A3. Meanwhile, these control materials were used as the internal quality control, and their coefficients of variation ( CV) were calculated. One-way ANOVA and t-Test were used to analyze the results. Results:The homemade materials at three concentrations showed good homogeneity[ F< F0.05(9, 20)]. When the control materials were stored at 2-8 ℃, the stable phases for the opened and closed bottles were 10 days and 15 days, respectively, and there was no statistically significant difference between the results of the first day( P>0.05). The control materials at three concentrations also showed good applicability and there were no matrix effects in 10 POC glucose systems. When the control materials were detected in the internal quality control, the CVs of the high, medium and low concentrations were 0.63%, 0.66% and 1.65%, respectively, which were all below 7.5%. Conclusions:The homemade human control materials of POC glucose testing showed good homogeneity, stability and applicability. They met the requirements of quality control in hospital settings, which provided a good application prospect of the quality management of POC glucose testing.

Evaluation of the targeted uncertainty in routine coagulation assay using EQA data / 中华检验医学杂志

Objective To establish the target measurement uncertainty(MU)of the routine coagulation assay according to the External Quality Assessment data(EQA)of routine coagulation assay. Methods Beijing Center for Clinical Laboratory(BCCL)established the target measurementuncertainty for routine coagulation assayswith the"up-down"methodon the basis of 93 clinical laboratoriesEQA datain BeijingThese assays includedActivated partial thromboplastine time(APTT), Fibrinogen(FBG), International Normalized Ratio(INR), Prothrombin time(PT), Thrombin time(TT)and D-dimer, Compared with CLIA′88,the proficiency of current coagulation assayswas observed.Results The MU of six routine coagulation assayscompared with CLIA ′88 showed that: The 90th percentile MU met the creteriain APTTof group B,FBG of group A&B&C,INR of group B and D-dimer of group B.The 75th percentile MU met the creteriainINR of group A&C,PT of group C.The medium met the creteriainAPTT of group A&C,PT of group A and INR of group D.Conclusions Target Measurement Uncertainty was establishedin routine coagulation assay by using EQA data only,whichcan simplify the procedure of determining MU and continuously update MU according to the frequency of EQA.It has good clinical practical value.However, the applicability of this method should also be considered.

Investigation on the distribution of critical value limits in adult patients in Beijing / 中华检验医学杂志

Objective To investigate the distribution of critical values of adults in Beijing, to provide the evidence for the formulation of the Standardized Management Guideline in Critical Values, in order to promote the accurate management of critical values.Methods A total of 110 398 data of critical values from the tertiary and above medical institutions during January 1 to May 31 in 2015 in Beijing were collected by the way of on-site inspection, covering the disciplines of hematology, clinical chemistry, coagulation and blood gas analysis.Fristly, the selected critical values were classified by the factor of admission departments and disease types,then were analyzed by using Kruskal-Wallis test, to compare the differences in each group.Secondly,the combined groups were classified by the factor of gender then were analyzed by using Mann-Whithey U test, to compare the differences in each group.Finally, the stratification thresholds of critical values were established.Results Except for the upper limits of Ca, pH, pCO2, Hb and the lower limits of Glu, pH, the rest of thresholds of critical values had significant differences due to different admission departments and disease types and/or gender.Conclusion Depending on the different admission departmentsces disease types and/or gender, hierarchical limit values on each critical value were formulated.

Investigation and analysis of internal quality control on clinical chemistry, clinical immunology and clinical hematology of mutual recognition laboratories in 142 medical institutions in Beijing / 中华检验医学杂志

Objective To investigate the internal quality control ( IQC ) on clinical chemistry , clinical immunology and clinical hematology in mutual recognition laboratories in medical institutions in Beijing.Methods By means of questionnaire survey and on -site investigation, fresh frozen serum and whole blood samples with assigned values by reference method were measured to investigate the status of IQC on clinical chemistry , clinical immunology and clinical hematology in 142 mutual recognition laboratories in medical institutions of Beijing,and results were analyzed.Results 142 copies of questionnaireson clinical chemistry, clinical immunology and clinical hematology were send out and 120, 97, and 101 laboratories returned the questionnaires respectively .The information feedback rate was 84.5%, 68.3% and 71.1%respectively .All the questionnaires were effective .Questionnaires survey results showed that more than 50%laboratories set up quality control goals and the most of the goals were probability for error detection ( Ped) 95%, probability for false rejection(Pfr)5%;About 70% laboratories usecd the same quality control plan for different tests ;The most frequently used quality control rules are 12s/13s/22s.On-site investigation showed that ,take the results of clinical chemistry for example , based on the desirable biological variation and WS/T 403 -2012 , most of the tests can't meet the quality control goalsunder the existing quality controlcondition.Conclusion Clinical laboratories should consider their actual situations , assess their own qualitylevels that they can reach , set reasonable quality standards for themselves , and make appropriateindividualized quality control plan.