National External Quality Assessment Scheme Research Articles

Coagulation factors VIII and factors IX testing practices in China: Results of the 5-year external quality assessment program

Background and aimsTesting for coagulation factors VIII (FVIII) and IX (FIX) plays significant importance in the diagnostic and treatment of hemophilia A and B. External quality assessment (EQA) scheme aimed to assess the participants’ performance of testing for coagulation factors and identify shortcomings in clinical practice. This study aimed to investigate the performance trends of the participating laboratories in China national external quality assessment Scheme (China NEQAS) for FVIII and FIX over a five-year period (2019–2023). Materials and methodsA total of ten external quality assessment (EQA) rounds were conducted from 2019 to 2023 in the China NEQAS for FVIII and FIX. The distribution of method, reagent and instrument were calculated. The trends of method- specific inter-laboratory coefficient of variation (CV) and pass rates were analyzed over 5 years. The dilutions for coagulation factor testing were also investigated. ResultsAll laboratories use one-stage assays to detect FVIII and FIX activity. The inter-laboratory overall CV decreased year by year (10.9 % to 9.3 % for FVIII and 13.5 % to 10.2 % for FIX), and the laboratory pass rate steadily increased (88.0 % to 93.4 % for FVIII and 81.3 % to 92.7 % for FIX). The majority of laboratories employed a single dilution methodology for the assessment of FVIII and FIX activity. The interlaboratory CV was elevated for the Siemens reagent (Actin FSL) during analysis of moderately abnormal FIX concentrations of EQA samples in most batches. ConclusionsThe implementation of the external quality assessment has contributed to facilitate the enhancement of testing quality. Chromogenic assay is a supplement to accurate determination when necessary. Laboratories may choose to perform dilution tests or direct assays to identify the presence of inhibitors, particularly when they are suspected.

The performance of quantitative D-dimer assays in Chinese clinical laboratories by analyzing data from National External quality Assessment Scheme

Background and aimsTo investigate performance of D-dimer assays in China and address analytical quality issues. Materials and methodsD-dimer assays data were collected from China National External Quality Assessment Scheme (China NEQAS) from 2014 to 2022. We analyzed reagents, assay results, reporting unit and cutoffs in 2022 China NEQAS. Interlaboratory coefficient variations (CVs) and influence of modified/unmodified test systems on CVs were investigated over 9 years. ResultsThere were 82 reagent brands in China NEQAS, but 55 reagent instructions did not indicate expression unit (DDU or FEU). Up to 7-fold of the ratio of max-to-min mean results was shown among different assays with same unit on the same sample. A prevalence of FEU (63.4%) over DDU (17.1%) was observed. Although 669 laboratories (37.9%) among 1766 laboratories used reagents without VTE exclusion claim, they also reported cutoffs. The CVs of only two assays were decreasing over years. CVs of modified test systems were higher than those of unmodified systems before improvement. ConclusionsExpression unit should be required to label in package inserts by regulatory authority. Laboratory professionals should follow instructions for use and prefer unmodified test systems for clinical safely application. Harmonization of reporting units through collaborative efforts is the promising step.

Whole blood clotting time: Current practices among Thailand National External Quality Assessment Scheme for blood coagulation member laboratories.

The Thai National Guidelines for Hemostatic Laboratory Testing were established in 2018. The guidelines recommend that the 20-min whole blood clotting time (20WBCT) method be used to diagnose/monitor snake bites. The aim of this study was to survey members of the Thailand National External Quality Assessment Scheme (NEQAS) for Blood Coagulation to investigate the use of 20WBCT testing compared between the 2021 post-guideline and 2007 pre-guideline periods. In July 2021, questionnaires were sent from the Faculty of Medicine Siriraj Hospital, Mahidol University to 521 Thailand NEQAS for Blood Coagulation member laboratories to survey their WBCT practices. Current WBCT practices were compared with pre-guideline WBCT practices, and chi-square test (x2) was used to test for differences between groups. Ninety-seven (18.6%) of 521 surveys were returned. Seventy-one laboratories (73.2%) reported knowing about 20WBCT from the Thai national guidelines. The reported average frequency of overall WBCT testing in 2021 was 12.4 times/month. The proportion of laboratories that reported using the 20WBCT test increased from 2.0% in 2007 to 46.4% in 2021 (p < 0.001), and the indications for performing WBCT were virtually unchanged from 2007 to 2021. The proportion of laboratories that reported having problems with WBCT testing decreased from 32.7% in 2007 to 16.5% in 2021. Despite our findings that almost three-quarters of respondent laboratories reported knowing about 20WBCT testing from the WBCT guidelines, and that WBCT-specific problems decreased significantly from 2007 to 2021, more work and training is needed to improve WBCT guideline dissemination, understanding, and adherence in Thailand.

Recommendations on the measurement and use of the alcohol consumption biomarker CDT. A position paper from the IFCC Working Group on CDT standardisation

BackgroundCarbohydrate deficient transferrin (CDT) is a biomarker for excessive alcohol consumption utilized in clinical and forensic medicine and workplace testing. Previously, many different analytical methods for CDT were used and the measurand varied considerably, making direct comparison of test results difficult. To end this confusion, the IFCC established a working group on CDT standardisation (WG-CDT) which completed its tasks in 2017. MethodsThis IFCC position paper by the WG-CDT summarizes state of the art information about the measurand and the analytical methods and gives concise recommendations for its utilization. ResultsThe results achieved by the CDT standardisation process led to accuracy improvements in national external quality assessment schemes over the years. A brief review of ROC based comparison studies with the traditional biomarkers (GGT, MCV, ALT and AST) discusses the bias resulting from inadequate study populations. In large groups of the general population the superior diagnostic performance of CDT is confirmed. ConclusionThe relationship between alcohol intake versus resulting CDT is discussed as well as the cutoff and measurement uncertainty. Concerning the application in practice, potential pitfalls are considered and recommendations handling both analytical and preanalytical caveats are given. Finally, some examples of serious misunderstandings in publications about CDT are addressed.

Results of a Pilot External Quality Assessment Scheme for Genetic Testing of Newborns with Spinal Muscular Atrophy.

This study aims to evaluate the ability of laboratories to perform spinal muscular atrophy (SMA) genetic testing in newborns based on dried blood spot (DBS) samples, and to provide reference data and advance preparation for establishing the pilot external quality assessment (EQA) scheme for SMA genetic testing of newborns in China. The pilot EQA scheme contents and evaluation principles of this project were designed by National Center for Clinical Laboratories (NCCL), National Health Commission. Two surveys were carried out in 2022, and 5 batches of blood spots were submitted to the participating laboratory each time. All participating laboratories conducted testing upon receiving samples, and test results were submitted to NCCL within the specified date. The return rates were 75.0% (21/28) and 95.2% (20/21) in the first and second surveys, respectively. The total return rate of the two examinations was 83.7% (41/49). Nineteen laboratories (19/21, 90.5%) had a full score passing on the first survey, while in the second survey twenty laboratories (20/20, 100%) scored full. This pilot EQA survey provides a preliminary understanding of the capability of SMA genetic testing for newborns across laboratories in China. A few laboratories had technical or operational problems in testing. It is, therefore, of importance to strengthen laboratory management and to improve testing capacity for the establishment of a national EQA scheme for newborn SMA genetic testing.

PB1112 UK National External Quality Assessment Scheme for Blood Coagulation (UK NEQAS BC) Emicizumab Programme, Survey July 2022 Results for Modified One-Stage Assay and Chromogenic Assay

PB1112 UK National External Quality Assessment Scheme for Blood Coagulation (UK NEQAS BC) Emicizumab Programme, Survey July 2022 Results for Modified One-Stage Assay and Chromogenic Assay

OC 23.5 National External Quality Assessment Scheme (NEQAS BC) and Welsh Blood Service (WBS) use Cold-Stored Platelets for External Quality Assessment (EQA) Scheme for Light Transmission Aggregometry (LTA)

OC 23.5 National External Quality Assessment Scheme (NEQAS BC) and Welsh Blood Service (WBS) use Cold-Stored Platelets for External Quality Assessment (EQA) Scheme for Light Transmission Aggregometry (LTA)

PB1039 Evaluation of External Quality Assessment Material for Activated Clotting Time on Point of Care Devices: United Kingdom National External Quality Assessment Scheme for Blood Coagulation Pilot Studies

PB1039 Evaluation of External Quality Assessment Material for Activated Clotting Time on Point of Care Devices: United Kingdom National External Quality Assessment Scheme for Blood Coagulation Pilot Studies

PB0616 UK National External Quality Assessment Scheme for Blood Coagulation (UK NEQAS BC) Evaluation of the Point of Care Fibrinogen Device

PB0616 UK National External Quality Assessment Scheme for Blood Coagulation (UK NEQAS BC) Evaluation of the Point of Care Fibrinogen Device

PB1041 Evaluation of External Quality Assessment Material on the Renovated Point of Care Device, United Kingdom National External Quality Assessment Scheme for Blood Coagulation Studies

PB1041 Evaluation of External Quality Assessment Material on the Renovated Point of Care Device, United Kingdom National External Quality Assessment Scheme for Blood Coagulation Studies

Internal Quality Control in Hemostasis Assays.

Internal quality control (IQC) for routine and specialist hemostasis testing represents a mandatory requirement for assays offered by clinical laboratories under International Organization for Standardization, Code of Federal Regulations, and Clinical and Laboratory Standards Institute standards. The underlying principle is that regular IQC audits the analytical performance of automated, semiautomated, and manual methods. This review investigates IQC practices, including benefits, limitations, frequency per time period or batch, sources of material used, primary supplier, third party or in-house, plus troubleshooting when IQC falls outside acceptance criteria. To assess IQC practice, the UK National External Quality Assessment Scheme (NEQAS) Blood Coagulation distributed a questionnaire to 1,200 participants enrolled in our scheme that collected details of the local practices for IQC testing. We received returns from 127 centers that described their local practices for the frequency of IQC, the type of IQC material employed, acceptance criteria for IQC data, and troubleshooting protocols for IQC failures. The data collected as part of an NEQAS BC questionnaire confirmed that all the participants returning answers to the questionnaire meet the standards for regular IQC testing for the hemostasis assays they perform.

First Round of External Quality Assessment Scheme for SARS-CoV-2 Laboratories During the COVID-19 Pandemic in Thailand.

The emergence of SARS-CoV-2 necessitated the rapid deployment of tests to diagnose COVID-19. To monitor the accuracy of testing across the COVID-19 laboratory network in Thailand, the Department of Medical Sciences under the Ministry of Public Health launched a national external quality assessment (EQA) scheme using samples containing inactivated SARS-CoV-2 culture supernatant from a predominant strain in the early phase of the Thailand outbreak. All 197 laboratories in the network participated; 93% (n=183) of which reported correct results for all 6 EQA samples. Ten laboratories reported false-negative results, mostly for samples with low viral concentrations, and 5 laboratories reported false-positive results (1 laboratory reported false positives and false negatives). An intralaboratory investigation of 14 laboratories reporting incorrect results revealed 2 main causes of error: (1) RNA contamination of the rRT-PCR reaction and (2) poor-quality RNA extraction. Specific reagent combinations were significantly associated with false-negative reports. Thailand's approach to national EQA for SARS-CoV-2 can serve as a roadmap for other countries interested in implementing a national EQA program to ensure laboratories provide accurate testing results, which is crucial in diagnosis, prevention, and control strategies. A national EQA program can be less costly and thus more sustainable than commercial EQA programs. National EQA is recommended to detect and correct testing errors and provide postmarket surveillance for diagnostic test performance.

UK NEQAS Haematology pilot scheme: Reticulocyte haemoglobin content quantitation.

Established parameters for the investigation of suspected iron deficiency have recognized limitations that affect their sensitivity and specificity. Reticulocyte haemoglobin content (RHC) is an early biomarker of iron deficiency or restriction, which also demonstrates response to iron therapy. RHC parameters are offered on all major automated haematology analysers. There is no external quality assessment (EQA) for RHC in the UK, restricting its wider clinical application. The UK National External Quality Assessment Scheme (UKNEQAS) for Haematology has completed a pilot study on the use of stabilized blood for RHC EQA. Blood was obtained from two JAK2 V617F mutation-positive, polycythaemia vera patients undergoing regular venesection, and from a healthy volunteer donor. Aliquots of each donation were distributed to users of Abbott, Horiba, Siemens and Sysmex automated analysers for RHC analysis on days 1, 3, 5 and 7. Results were received from 20 laboratories using four different platforms. The daily mean and standard deviation (SD) were calculated for each aliquot, by day of analysis and platform. With RHC there was no significant within-platform difference (p> 0.5) between testing days, although there were statistically significant differences (p< 0.001) between different platforms. The greatest difference was seen between Abbott MCHr and Horiba RhCc (-6.14 ± 1.25 pg). Despite inter-platform differences, it was possible to define iron deficient, borderline, and normal cut-offs to classify 95% of results correctly. The results demonstrate that it is possible to provide RHC EQA material using UKNEQAS standard procedures. The results are clinically relevant but indicate a requirement for inter-user comparison.

External Quality Assessment Data for Investigation of von Willebrand Disease: Focus on Relative Utility of Contemporary Functional von Willebrand Factor Assays. The United Kingdom National External Quality Assessment Scheme (UK NEQAS) Experience.

Von Willebrand disease (VWD) is one of the most common hereditary bleeding disorders. Effective management of patients and their families depends on accurate diagnosis and subtype classification, and quality assurance including participation in proficiency testing programs is essential to ensure the accuracy of the panel of assays required to achieve this diagnosis. We report here findings from recent external quality assessment (EQA) exercises, as well as from a questionnaire about diagnostic practices employed by centers in the United Kingdom National Quality Assessment Scheme (UK NEQAS) performing von Willebrand factor (VWF) assays. Plasma samples from donors with VWD, "normal" donors, the International Society for Thrombosis and Haemostasis Scientific Subcommittee (ISTH SSC) plasma standard, and whole blood samples were sent to participants in the UK NEQAS BC program for VWF investigation. Calibration of lot#5 of the ISTH SSC plasma standard was shown to give improved comparability between the recovered value from an EQA exercise and the assigned potency for VWF activity assays. Diagnostic accuracy and precision amongst UK NEQAS participants was good, with an average 99% of centers reporting the correct interpretation for normal, type 1 and type 2 VWD samples, 100% diagnostic accuracy for centers performing FVIII binding assays, and good agreement amongst centers performing multimeric analysis. Genetic analysis of the VWF gene by specialist centers demonstrated errors in the genotyping process in one center, but also demonstrated failings in the interpretation of results in other centers. Despite evidence of good laboratory accuracy and precision in their assays, a questionnaire identified marked variation in diagnostic criteria employed, underlining the importance of guidelines to support the diagnosis of VWD.

External quality assessment scheme for HbA1c assays in Thailand: A 5-year experience

BackgroundThailand National External Quality Assessment Scheme (NEQAS) for HbA1c was established to evaluate the quality of HbA1c assays in Thailand in 2016. MethodsHbA1c results from participating laboratories were compared to the target value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference system. ResultsThe pass rates of participating laboratories during 2016–2020 were72–88%. The mean bias ranged between −0.19 and 0.20% of HbA1c. SD ranged from 0.30 to 1.08% of HbA1c. The overall coefficients of variation ranged from 4.46-15.66%. ConclusionsPerformance evaluation using IFCC assigned values indicated that different assay methods had an effect on HbA1c results. Participation in external quality assessment programs for HbA1c analysis is essential for improving laboratory quality and benefiting patient management.

External quality control of microbiological testing in Polish medical diagnostic laboratories in 2020

&lt;br&gt;&lt;b&gt;Introduction:&lt;/b&gt;The paper presents the course of external quality control programmes organised in 2020 by the Centre of Quality Control in Microbiology (CQCM), including the 27&lt;sup&gt;th&lt;/sup&gt; edition of the Polish National External Quality Assessment Scheme in Microbiology POLMICRO.&lt;/br&gt; &lt;br&gt;&lt;b&gt;Aim:&lt;/b&gt;The assessment of the microbiological diagnostics’ quality carried out by Polish laboratories based on results of the POLMICRO, POLMICRO/MIKOLOGIA (MYCOLOGY), and POLMICRO/SSE programmes.&lt;/br&gt; &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt;The participants’ responses from all rounds conducted in 2020 were analysed, i.e. five rounds of the POLMICRO programme, two rounds of the POLMICRO /MIKOLOGIA programme, and one round of POLMICRO/SSE.&lt;/br&gt; &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt;Positive evaluation in all rounds in the annual cycle were obtained by 90,1% of POLMICRO, 92,5% POLMICRO/MIKOLOGIA, and 100% POLMICRO/SSE participants.&lt;/br&gt; &lt;br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Laboratories participating in the CQCM programmes demonstrated skills in the identification, antimicrobial susceptibility testing, and detection of resistance mechanisms of pathogenic microorganisms. The area of internal quality control of antimicrobial susceptibility testing requires improvement, especially the selection of reference strains.&lt;/br&gt;

External quality assessment for one-stage and chromogenic factor IX assays in samples containing Alprolix (rFIXFc) or Idelvion (rIX-FP) and evidence that UK National External Quality Assessment Scheme for blood coagulation samples are commutable with patient samples.

There may be clinically relevant differences between results of different FIX assays in samples containing extended half life FIX concentrates requiring regular surveillance of assay results through proficiency testing exercises. Control materials used in proficiency testing must be commutable, that is have the same inter-assay properties as those demonstrated by authentic clinical samples when measured by different analytical methods. We assessed relationships between results with different FIX assays and commutability of UK National External Quality Assessment Scheme (NEQAS) materials containing rIX-FP (Idelvion) or rFIXFc (Alprolix) by comparing results obtained using widely used one-stage and chromogenic assays during a proficiency testing exercise with results obtained when analysing a series of individual patient samples using the same assay systems. NEQAS samples prepared by addition of either Idelvion or Alprolix to FIX deficient plasma were sent to 76haemophilia centres in Europe. A total of 18 Idelvion and 22 Alprolix patient samples were assayed in a single centre. Two chromogenic and two one-stage assays were compared. The pattern of results obtained for NEQAS samples and patient samples was similar. In all cases, the NEQAS sample data point was within the scatter of patient sample data in plots of patient sample results showing one-stage assay results using Synthasil or Actin FS plotted against chromogenic assay results with Biophen or Rox chromogenic FIX kits. This indicates that the NEQAS samples containing Idelvion or Alprolix were commutable and therefore suitable for use in proficiency testing exercises.

Interpretative comments - need for harmonization? Results of the Croatian survey by the Working Group for Post-analytics.

IntroductionInterpretation of laboratory test results is a complex post-analytical activity that requires not only understanding of the clinical significance of laboratory results but also the analytical phase of laboratory work. The aims of this study were to determine: 1) the general opinion of Croatian medical biochemistry laboratories (MBLs) about the importance of interpretative comments on laboratory test reports, and 2) to find out whether harmonization of interpretative comments is needed.Materials and methodsThis retrospective study was designed as a survey by the Working Group for Post-analytics as part of national External Quality Assessment (EQA) program. All 195 MBLs participating in the national EQA scheme, were invited to participate in the survey. Results are reported as percentages of the total number of survey participants.ResultsOut of 195 MBLs, 162 participated in the survey (83%). Among them 59% MBLs implemented test result comments in routine according to national recommendations. The majority of laboratories (92%) state that interpretative comments added value to the laboratory reports, and a substantial part (72%) does not have feedback from physicians on their significance. Although physicians and patients ask for expert opinion, participants stated that the lack of interest of physicians (64%) as well as the inability to access patient’s medical record (62%) affects the quality of expert opinion.ConclusionAlthough most participants state that they use interpretative comments and provide expert opinions regarding test results, results of the present study indicate that harmonization for interpretative comments is needed.

The concurrence of the current postanalytical phase management with the national recommendations: a survey of the Working Group for Postanalytics of the Croatian Society of Medical Biochemistry and Laboratory Medicine.

IntroductionThe detection and prevention of errors in the postanalytical phase can be done through the harmonization and standardization of constituent parts of this phase of laboratory work. The aim was to investigate how well the ongoing management of the postanalytical phase corresponds to the document “Post-analytical laboratory work: national recommendations” in Croatian medical biochemistry laboratories (MBLs).Materials and methodsAll 195 MBLs participating in the national external quality assessment scheme, were invited to undertake a part in a survey. Through 23 questions the participants were asked about management of the reference intervals (RI), delta check, reflex/reflective testing, postanalytical quality indicators and other parts of the postanalytical phase recommended in the national recommendations. The results are presented in numbers and percentages.ResultsOut of 195 MBLs, 119 participated in the survey, giving a response rate of 61%. Not all of the respondents provided answers to all the questions. Delta check has not been used in 59% (70/118) of the laboratories. Only 22/113 (20%) laboratories use reflex and/or reflective testing. In 53% of the laboratories, critical results were reported within 30 minutes of the confirmation of the results. In 34% (40/118) of the laboratories, turnaround time and reporting of critical results are two most often monitored postanalytical quality indicators.ConclusionThe results showed the critical results reporting and monitoring of postanalytical quality indicators are in the line with the recommendations. However, the management of RI verification, the use of delta check and reflex/reflective testing still must be harmonized among Croatian MBLs.

Anti‐PF4 testing for vaccine‐induced immune thrombocytopenia and thrombosis and heparin induced thrombocytopenia: Results from a UK National External Quality Assessment Scheme exercise April 2021

BackgroundVaccine‐induced immune thrombocytopenia and thrombosis (VITT) following the administration of the AstraZeneca (AZ) ChAdOx1 nCOV‐19 vaccine has recently been reported. The associated clinical and laboratory features have included thrombosis at unusual sites, thrombocytopenia, and raised D‐dimers with positivity for IgG anti‐platelet factor 4 (PF4) antibodies. ObjectivesA UK National External Quality Control Assessment Scheme external quality control exercise was carried out by distributing liquid and lyophilized samples from a subject with VITT, a pool of samples from subjects with classical heparin‐induced thrombocytopenia (HIT), and a non‐VITT/non‐HIT case to 85 centers performing HIT testing. MethodsParticipating centers employed their locally validated testing methods for HIT assays. ResultsThe lyophilized and liquid samples were found to be commutable for the ELISA assays used in the detection of anti‐PF4 antibodies. The Aeskulisa, Stago, Hyphen, and LIFECODES anti‐PF4 ELISA assays successfully detected the VITT antibody, whereas the Acustar HIT, Werfen LIA, and the Stago STIC assays did not. ConclusionIt is important that clinical and laboratory teams are aware of the limitations of some anti‐PF4 assays when using them to aid diagnosis of VITT syndrome.