External Quality Assessment Research Articles

How has the external quality assessment/proficiency testing of semen analysis been developed in the past 34 years: a review.

Male infertility has become an important issue of global concern. Semen analysis is the cornerstone of male fertility assessment. External quality assessment (EQA) of sperm concentration, motility, and morphology is widely recognized in the world. However, over the past 34 years, the implementation of EQA for semen analysis has varied across different countries, and there is no global consensus. The goal of this paper is to first explore the overall development of EQA during this period. Secondly, it aims to discuss the extent of difference of participating laboratories in different countries. Finally, the paper examines the differences in EQA programs developed by various EQA providers in order to seek a global standard. In total, 29 papers met the inclusion criteria and were included in this review. There is inconsistent in the implementation of EQA across different countries, and there is no global consensus. Policies for EQA of semen analysis vary from country to country. Some countries mandate laboratory participation, while others permit voluntary involvement. Different EQA organizers choose different ways to calculate assigned value and acceptance limits. The coefficient of variation (CV) for each EQA item was large. The CVs of concentration, motility, morphology, and viability were 12.7-138.0 %, 17.0-127.0 %, 7-375 %, and 6-41.1 %, respectively. The results of the semen analysis varied considerably among the participating laboratories. The collaborative efforts of national policymakers, EQA organizers, and all participating laboratories are essential to improving the current situation.

Selection and Evaluation of Suitable Quality Control Strains for Meropenem Antimicrobial Susceptibility Testing through Preliminary External Quality Assessment

BackgroundQuality control (QC) of carbapenem susceptibility testing for Gram-negative bacteria faces challenges due to limited measuring ranges and the lack of suitable QC strains. This study aimed to select and evaluate QC strains for meropenem antimicrobial susceptibility testing (AST) through a pilot external quality assessment (EQA). MethodsCandidate QC strains for meropenem AST were selected based on primary AST data and genomic information from the Japan Antimicrobial Resistant Bacterial Bank. Phenotype stability was verified through serial passaging and MIC comparison with original strains. The validated broth microdilution method was used to determine the target MIC value in a pilot EQA involving 47 clinical laboratories in Japan using ten different AST methods. ResultsTwo strains, Citrobacter freundii JBBDAJB-19-0032 (Strain-A) and Enterobacter hormaechei subsp. steigerwaltii JBEBAAB-19-0102 (Strain-B), both carrying blaIMP-1, were selected as candidate QC strains. The meropenem MICs for Strain-A and Strain-B were 4 mg/L and 2 mg/L, respectively. In the pilot EQA, 43 laboratories reported appropriate results for Strain-A and 40 laboratories reported appropriate results for Strain-B. The MIC range was 2-8 mg/L for Strain-A and 1-4 mg/L for Strain-B. However, 19 and 12 laboratories, respectively, reported out-of-range MICs using AST plates on the MicroScan WalkAway (Beckman Coulter). Inappropriate results were reported by four and seven laboratories, respectively, using common methods for Strain-A and Strain-B, respectively. ConclusionsThe candidate QC strains selected for this study are suitable for meropenem AST EQA, except when the measuring range of certain methods does not match their QC range.

Screening kolorektálního karcinomu v České republice – minulost, současnost a budoucnost

The National Colorectal Cancer Screening Program has been conducted in the Czech Republic since 2000 and serves as an example of interdisciplinary collaboration. Specialists from gastroenterology, general practice, gynecology, and clinical biochemistry are involved in the program. It is based on two primary methods: the screening fecal immunochemical test for occult bleeding (iFOBT, FIT) and preventive colonoscopy (FOBT-positive colonoscopy and screening colonoscopy). The program‘s effectiveness is evidenced by the high number of detected colorectal precancerous and malignant lesions. Between 2006 and 2023, a total of 531,362 preventive colonoscopies were performed, diagnosing 202,575 patients with adenomas (38.1%) and 14,473 patients with cancers (2.7%). Program quality is monitored by indicators focused on both organization (target population coverage) and screening methods. Coverage with screening tests in a 2-year interval has consistently ranged around 30%, except between 2020 and 2021 during the COVID-19 pandemic (27%), reaching 30.0% in 2023. Non-screening tests also affect epidemiological indicators, with total coverage by all relevant methods in a 2-year interval in 2023 amounting to 37.5%. Colonoscopies are evaluated using six parameters (number of examinations, bowel preparation quality, total colonoscopies, and adenoma detection rate in total, in both women and men). In 2023, 72% of screening colonoscopy centers met all of these indicators. FOBT analyzers now must have the regular external quality assessment (EQA), which should help stabilize test positivity, standing at 9.1% in 2023. Thanks to the National Colorectal Cancer Screening Program, favorable epidemiological trends have been observed, with a 32.3% decrease in incidence and a 47.8% decrease in mortality between 2000 and 2022. The future of the program lies in its further optimization, with a goal of both increasing coverage of the target population by examination and quality improvement, ensuring the program’s feasibility and efficiency. Key words: colorectal cancer – adenoma – screening – colonoscopy – fecal immunochemical test – quality indicators

Evaluation of revised UK-NEQAS CSF-xanthochromia method for subarachnoid hemorrhage: outcome data provide evidence for clinical value.

Subarachnoid haemorrhage (SAH) has a high morbidity and mortality and requires prompt diagnosis. In patients with negative findings on computed-tomogram of the brain (CT-Brain) cerebrospinal fluid (CSF)-xanthochromia is considered the test of choice if performed 12 h or more after symptom onset. We audited the accuracy, usefulness and timing of CSF-xanthochromia testing and the interpretation of equivocal CSF-xanthochromia findings. We also investigated mortality outcomes for defined subsets of patients. A retrospective audit of CSF-xanthochromia tests over 8 years was performed. The service uses the revised UK-NEQAS (United Kingdom National External Quality Assessment Service) method. We analysed 543 cases (F=299, median age 44yrs) with 19 cases (3.5 %) having SAH. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CSF-xanthochromia testing were 100 , 98.1, 65.9, 100 % respectively (equivocal results were counted as positives). 280 cases (F=153, median age 43yrs) had LP performed more than 24 h after the onset of headache (median time to LP=72 h). The sensitivity and specificity of the CSF-xanthochromia were 100 and 97.4 % in this group with NPV 100 % and PPV 66.6 %. 183 (65.4 %) CSF- xanthochromia negative cases in this subgroup had follow up data and survived without SAH occurring in the 12months follow up. In this study, supported by follow up outcome data, we show that CSF-xanthochromia testing using the revised UK-NEQAS method is fit-for-purpose for the use as a second line test to exclude SAH in patients with negative CT-brain including delayed presentation more than 24 h after headache onset.

Evaluation of 3-year tuberculosis external quality assessment results of public health laboratories.

Background We aimed to evaluate the 3-year participation status of tuberculosis (TB) laboratories in public health laboratories (PHL) tuberculosis external quality assessment (EQA) and EQA results. Method During 2018-2020, PHLs participated in the EQA programme organized annually by the National Tuberculosis Reference Laboratory (NTRL). Five kinds of EQA samples were sent to the participating laboratories on three parameters, including microscopy, culture and phenotypic first-line drug susceptibility testing and they were asked to perform according to the standard protocol. The results were taken over by the Tuberculosis Laboratories Surveillance Network (TULSA) web system and analysed. Results A total of 24 PHLs participated in the EQA in 2018; 30 in 2019 and 23 in 2020. In terms of sensitivity, specificity, accuracy and reproducibility in microscopy, respectively, in 2018, 20 of the laboratories were 100%, 4 of them 80%, and in culture 16 of them were 100% and 2 of them 80%; in 2019, 28 of them were 100%, 2 of them 80%, and in culture 11 of them were 100%, 6 of them 80%, 1 of them 60%; in 2020, 20 of them were 100%, 3 of them 80%, and in culture 13 of them were 100% and 3 of them 80%. Conclusion It is beneficial for laboratories working on TB to participate in EQA in terms of evaluating the accuracy and reliability of the method used.

Coefficients of variation analyses of internal quality control status for blood lead in China from 2015 to 2023.

Blood lead test is widely conducted in Chinese laboratories, while the imprecision of blood lead measurement based on internal quality control (IQC) across China has not been comprehensively evaluated nowadays. Using the IQC data of blood lead collected through a web-based external quality assessment (EQA) reporting system, we analyzed current coefficients of variation (CVs) of blood lead from 2015 to 2023 among Chinese laboratories. Two allowable total error (TEa) imprecision levels from EQA were applied to calculate the pass rates, namely percentages of laboratories meeting precision quality specifications. Besides, CV values and pass rates by different subgroups were further performed to assess potential differences. Generally, median CV values significantly declined year by year from 6.8% in February 2015 to 5.9% in March 2023. The pass rates based on 1/3 TEa showed upward trends increasing from 15.3% in February 2015 to 20.0% in March 2023, but these percentages were non-ideal with less than 25%. No significant differences in CVs were found between tertiary hospitals and non-tertiary hospitals and between accredited and non-accredited laboratories. Significant time trends were observed in tertiary hospitals and nonaccredited laboratories. As for manufacturers, Bohui and self-made QC sample were most widely-used with obvious interannual declining trends of CVs. The CVs of blood lead demonstrated continuous overall improvements in the past twenty years. However, relatively lower pass rates indicated the non-ideal imprecision performance, and more proper performance specifications are warranted. Thus, imprecision improvement and ongoing investigation for blood lead IQC are still needed.

International external quality assessment study for detection of monkeypox virus by PCR supporting laboratory preparedness during the 2022–2023 mpox outbreak and beyond

BackgroundDiagnostic capabilities and correspondent External Quality Assessments (EQA) are key for outbreak preparedness. To support diagnostic facilities with a quality assessment of newly established monkeypox virus (MPXV) molecular diagnostic workflows, Quality Control for Molecular Diagnostics (QCMD) and the Bundeswehr Institute of Microbiology (IMB) piloted an international EQA study conducting four challenges from autumn 2022 to summer 2023 during the global mpox outbreak. ObjectivesTo assess the performance (sensitivity/specificity) of molecular assays used by diagnostic laboratories. Study designInactivated EQA panels were prepared and distributed containing seven samples of clade Ia and clade IIb MPXV strains at different viral concentrations, two specificity controls with other zoonotic orthopoxviruses (vaccinia and cowpox virus) and a negative control. Assessment was based on reported qualitative testing results. ResultsIn this outbreak-related EQA study, a total of 192 laboratories from 37 countries reported 346 qualitative datasets. Overall, core samples were correctly detected by approximately 92 % of participants in all four challenges. While sensitivity performance was acceptable in at least 90 % of datasets correctly reported even for educational MPXV-positive samples with low viral concentration [102 genome equivalents (GE)/mL], several laboratories reported the educational specificity controls as false positives or were unable to differentiate MPXV from related orthopoxviruses. ConclusionsMpox is now a globally occurring infection with a demand for quality-assured diagnostic capabilities. The newly established EQA scheme presented here, offers a multi-purpose panel for orthopoxviruses with a focus on MPXV which will continue to ensure diagnostic quality in clinical settings with up-to-date sample panels.

The EuroFlow PIDOT external quality assurance scheme: enhancing laboratory performance evaluation in immunophenotyping of rare lymphoid immunodeficiencies.

The development of External Quality Assessment Schemes (EQAS) for clinical flow cytometry (FCM) is challenging in the context of rare (immunological) diseases. Here, we introduce a novel EQAS monitoring the primary immunodeficiency Orientation Tube (PIDOT), developed by EuroFlow, in both a 'wet' and 'dry' format. This EQAS provides feedback on the quality of individual laboratories (i.e.,accuracy, reproducibility and result interpretation), while eliminating the need for sample distribution. In the wet format, marker staining intensities (MedFIs) within landmark cell populations in PIDOT analysis performed on locally collected healthy control (HC) samples, were compared to EQAS targets. In the dry format, participants analyzed centrally distributed PIDOT flow cytometry data (n=10). We report the results of six EQAS rounds across 20 laboratories in 11 countries. The wet format (212 HC samples) demonstrated consistent technical performance among laboratories (median %rCV on MedFIs=34.5 %; average failure rate 17.3 %) and showed improvement upon repeated participation. The dry format demonstrated effective proficiency of participants in cell count enumeration (range %rCVs 3.1-7.1 % for the major lymphoid subsets), and in identifying lymphoid abnormalities (79.3 % alignment with reference). The PIDOT-EQAS allows laboratories, adhering to the standardized EuroFlow approach, to monitor interlaboratory variations without the need for sample distribution, and provides them educational support to recognize rare clinically relevant immunophenotypic patterns of primary immunodeficiencies (PID). This EQAS contributes to quality improvement of PID diagnostics and can serve as an example for future flow cytometry EQAS in the context of rare diseases.

Validation, implementation and quality control of a Torque Teno Virus qPCR in a multinational clinical trial

BackgroundImmunosuppressive medication after organ transplantation is usually dosed through therapeutic drug monitoring. Trough levels of antirejection medication however, do not adequately predict rejection or infections. The TTVguideIT trial is a multinational clinical trial evaluating the safety of Torque Teno Virus (TTV) load assessed by qPCR, as an alternative to trough level tacrolimus dosing. MethodsPrior to, and during the clinical trial, the inter-and intra-laboratory variability, accuracy, and precision of the TTV R-GENE® assay was evaluated through analysis of internal quality control (IQC), external quality assessment (EQA) and linearity panels performed by the thirteen participating clinical virology laboratories, each using their standard testing platforms. ResultsIQC samples with a target of 4 log10 copies/mL (cp/mL) were tested by the participating laboratories 130 times during the implementation phase and 987 times during the trial phase. They showed excellent accuracy, with an inter-laboratory standard deviation (SD) of 0.17 log10 cp/mL, and an intra-laboratory SD of 0.03 to 0.20 log10 cp/mL during the implementation phase, and an inter-laboratory SD of 0.19 log10 cp/mL, and an intra-laboratory SD 0.07 to 0.18 log10 cp/mL during the trial phase. Three EQA panels and three linearity panels showed similarly small variability during implementation as well as within the trial phase. ConclusionThis data shows that TTV load measurement can be standardized for use in a multinational clinical trial. By using IQC, LP and EQA samples, the quality and integrity of the assay can be compared between laboratories and precise and accurate results can be generated.

Glucose inhibitor tubes in Croatian laboratories: are we doing well?

Reliable and accurate measurement of blood glucose concentration is of crucial importance for making clinical decisions in diagnosis diabetes, gestational diabetes and impaired fasting glucose tolerance. Survey was performed in form of questionnaire. Questionnaire was sent to all Croatian laboratories (N = 204) in electronic form using SurveyMonkey cloud-based software (SurveyMonkey, Inc., San Mateo, USA) as an extra-analytical module of the Croatian EQA (External Quality Assessment) provider Croatian center for external quality assessment (CROQALM) in June 2023. In total 148 (73%) of laboratories responded to the survey. Large proportion of laboratories never use glucose inhibitor tubes for random glucose measurement (more than half) or for glucose function tests (one quarter). Only three laboratories use recommended glycolysis inhibitor citrate. Many other inhibitors are also used, even if some of them are not recommended for plasma glucose measurement. Glucose is almost never (93%) sampled on ice when glucose inhibitor tube is not available. Laboratories in Croatia do not follow the recommended procedures regarding glycolysis inhibitors for glucose determination.

Clinical application of an optimized reference measurement procedure for serum digoxin using bracketing calibration method by ID-LC-MS/MS.

Digoxin, a cardiac glycoside, is widely used in the treatment of cardiovascular diseases. Due to its narrow therapeutic range, precise monitoring of its blood concentration is essential. Areference measurement procedure (RMP) is pivotal for ensuring result accuracy and comparability. The RMP for serum digoxin by ID-LC-MS/MS was optimized with sample pre-treatment and detection processes, and the bracketing calibration method was used, which facilitates more accurate measurement, especially for extreme concentrations. The performance of this optimized RMP was thoroughly evaluated. The limit of detection (LoD) was 0.05 ng/mL (0.06 nmol/L) and the lowest limit of quantification (LLoQ) was 0.10 ng/mL (0.13 nmol/L). The intra- and inter-assay imprecisions were 2.24%, 2.51%, 1.40% and 1.72%, 1.65%, 0.97% at 0.5, 2.0, 5.0 ng/mL, respectively. Recoveries were 99.63 to 101.42% and thelinear response ranged from 0.1 to 10.0 ng/mL. The relative bias was 0.41% and 2.00% of our results compared with the median of all participating reference laboratories for IFCC-RELA (External Quality Assessment Scheme for Reference Laboratories in Laboratory Medicine) 2023A and 2023B. The uncertainty, calibration and measurement capability (CMC) of this method were also evaluated. The optimized RMP was applied in the Trueness Verification Plan of Southern China, which indicates significant differences among clinical systems, highlighting the need for standardization efforts. In addition, two commonly used clinical systems which employed immunoassay methods were compared with this optimized RMP, and 26 individual serum samples were analyzed. The good correlations indicate the feasibility of standardization for serum digoxin. The optimized RMP serves as an accurate reference baseline for routine methods, aiming to enhance the accuracy and precision of measurements in clinical laboratories.

Analytical evaluation of eight qualitative FIT for haemoglobin products, for professional use in the UK.

Qualitative faecal immunochemical tests for haemoglobin (FIT), for triaging for colorectal cancer investigations, are available for professional use. The aim was to evaluate these lateral flow tests. No previous analytical evaluations have been published. Analytical sensitivity (AS) was assessed using samples spanning manufacturers' quoted AS, concurrently with the quantitative OC-SENSOR PLEDIA, using Hb-spiked samples in manufacturers' buffer (n≥5;≤9-99 ng Hb/mL buffer), Hb-spiked faeces (n=6;<2-34 µg Hb/g faeces) and natural faeces (n=17;<2-82 μg/g); concentrations for 50 %/100 % Hb-detected were compared with quoted AS. Compatibility with two external quality assessment schemes (EQAS) (n=9; 3-96 μg/g) and prozone compared with manufacturers limits (n=9; 2,500-10,000,000 ng/mL) were tested. Ease-of-use by five healthcare personnel was assessed. Seven products showed lower AS (ng/mL) than manufacturers quoted using Hb-spiked aqueous samples compared with OC-SENSOR, one was equivocal; six manufacturers quoted AS in µg/g, five showed lower AS using Hb-spiked faeces. Results were similar but less consistent for natural faeces. Result lines for low concentrations can be faint and open to interpretation. Results were consistent with manufacturers quoted prozone limits. Results were consistent for seven products for two EQAS. The ease-of-use was 68.5-85.6 %; products with lower scores could be improved with better instructions and sample bottles. AS was lower for seven products (aqueous samples) and five products (aqueous/faecal samples) and prozone consistent with manufacturers expected concentrations, compared with OC-SENSOR. EQAS results were mostly consistent with expected results; products can be used by healthcare professionals, though some manufacturer improvements could be made.

A novel method for the preparation of reproducible, stable, and non-infectious quality control materials for Chlamydia trachomatis nucleic acid detection.

Chlamydia trachomatis (CT) is a significant sexually transmitted pathogen known to evoke severe complications, including infertility. Nucleic acid amplification tests (NAATs) are recommended by the World Health Organization to detect CT infection. Furthermore, the establishment of methods, performance validation, internal quality control, and external quality assessment for CT NAATs necessitate the utilization of quality control materials (QCs). QCs are specimens or solutions that are analyzed for quality control purposes in a test system. In this study, we established a novel cell line that stably integrates CT amplification target sequences for producing QCs for CT NAATs. Utilizing clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 technology, we integrated the CT plasmid-mediated sequence (comprising the full length of the cryptic plasmid and the major outer membrane protein gene, 9,136 bp) into the MUC4 gene of HEK293T cells. Positive clones were screened through flow cytometric sorting, single-cell culture, and PCR-based identification, followed by the establishment of stable cell lines. These cells were then processed using optimized cell preservation procedures to prepare QCs. The sequence insertion copy number was confirmed by real-time quantitative PCR. This novel CT QCs demonstrate excellent clinical applicability, non-infectiousness, quantifiability, and stability. With an integrated sequence exceeding 9 kb in length, it offers exceptional flexibility for adapting to new kit developments. Furthermore, maintaining a well-defined copy number and stable shelf life, the QCs closely aligns with the quality control requirements of CT NAATs. This study presents an innovative method for preparing QCs for CT nucleic acid detection, making a valuable contribution to improving the performance of CT NAATs.IMPORTANCEUntreated CT infections impose significant burdens on individuals and communities, underscoring the importance of early and accurate testing via CT NAATs for disease control. QCs are instrumental in identifying testing process issues. Hence, we developed a cell line integrating CT-amplified target sequences as readily accessible non-infectious QCs. These QCs boast several advantages: the integration of over 9 kb of CT sequence allows for broad applicability, allowing flexible adaptation to the development of new kits. Confirming the CT sequence copy number provides a reliable basis for QC concentration preparation and kit detection limit evaluation. Optimized preservation protocol enhances QC stability during storage, facilitating convenient shipment to clinical laboratories at ambient temperatures. In summary, our novel CT QCs offer a powerful tool for improving CT NAAT performance and present a fresh perspective on QC preparation for detecting nucleic acids from intracellular parasitic pathogens.

Expedient measurement of total protein in human serum and plasma via the biuret method using fiber optic probe for patient samples and certified reference materials.

The biuret method is currently recognized as a reference measurement procedure for serum/plasma total protein by the Joint Committee for Traceability in Laboratory Medicine (JCTLM). However, as the reaction involved in this method is highly time-dependent, to ensure identical measurement conditions for calibrator and samples for high accuracy, a fast and simple measurement procedure is critical to ensure the precision and trueness of this method. We measured serum/plasma total protein using a Cary 60 spectrophotometer coupled with a fiber optic probe, which was faster and simpler than the conventional cuvette method. The biuret method utilizing alkaline solutions of copper sulfate and potassium sodium tartrate was added to the sample and calibrator (NIST SRM 927e) incubated for 1h before measurement. A panel of samples consisting of pooled human serum, single donor serum, and certified reference materials (CRMs) from three sources were measured for method validation. Sixteen native patient samples were measured using the newly developed biuret method and compared against clinical analyzers. Additionally, the results of three cycles of a local External Quality Assessment (EQA) Programme submitted by participating clinical laboratories were compared against the biuret method. Our biuret method using fiber optic probe demonstrated good precision with within-day relative standard deviation (RSD) of 0.04 to 0.23% and between-day RSD of 0.58%. The deviations between the obtained values and the certified values for all three CRMs ranged from -0.38 to 1.60%, indicating good method trueness. The routine methods using clinical analyzers were also found to agree well with the developed biuret method using fiber optic probe for EQA samples and native patient samples. The biuret method using a fiber optic probe represented a convenient and reliable way of measuring serum total protein. It also demonstrated excellent precision and trueness using CRMs and patient samples, which made the method a simpler candidate reference method for serum protein measurement.

B-324 Pilot Study Result of EQA for Fecal Immunochemical Test for Hemoglobin Using a Novel Ready-to-Use Sample Material

Abstract Background The primary screening method for colorectal cancer is fecal immunochemical test (FIT) detecting human hemoglobin (Hb) in feces. There are several tests on the market both for automated analyzers and point-of-care testing (POCT). To ensure high quality results, the tests should be monitored with appropriate quality assessment procedures including participation in external quality assessment (EQA) programs. By participating in an EQA program using a stool-like material, clinical laboratories and POCT sites can fulfil the ISO 15189 requirements of monitoring the complete laboratory process from pre- to postanalytical phases in addition to the quantitative analytical phase of FIT. Here we present the first results of an international EQA pilot study for quantitative FIT using a novel ready-to-use stool-like material, performed by EQA provider Labquality. Methods 40 participants from 8 countries using 9 different FIT reagents were recruited for the pilot study performed in 2023. A set of artificial stool samples containing human hemoglobin uniformly was shipped to the participants at ambient temperature. The sample material is developed by HECTEF (Health Care Technology Foundation, Japan). The participants were instructed to collect the sample with their test specific sample collection kit and perform analysis according to the manufacturer’s instructions as a regular patient sample. Quantitative results (µg Hb/g feces) and qualitative interpretations (positive/negative) were reported in Labquality’s electronic platform LabScala. The quantitative target value was a method group consensus mean. A questionnaire regarding the usability of the sample material was sent to all participants. Results Sample S001 contained no Hb and all participants (40/40) reported a result corresponding to the lower detection limit of their test in use or a low numeric result most likely explained by unspecific background. All reported a negative interpretation. Sample S002 was a high positive sample for Hb. The measured value exceeded the upper detection limit of 4/9 tests (Exdia iFOB, Precision Biosensor; Fecal Occult Blood (iFOB) Neo, Boditech; FOB Test, VedaLab; NADAL FOB Quant test, Nal von Minden). The mean values and CV% were 116 µg/g and 8% for iFOBT, Aidian; 192 ug/g and 4% for Standard iFOB FIA, SD Biosensor; 144 µg/g and 45% for FOB assay kit FOB Gold, Sentinel Diagnostics (different clinical chemistry analyzers used); 91 µg/g and 26% for OC-Sensor FIT, Eiken Chemical. All participants responded a positive qualitative clinical interpretation. The majority of the responders on the feedback questionnaire (26/35) found the samples to be easy to use including comments of the sample being user-friendly and ready-to-use, resembling a patient sample and easy to apply with the test specific sample collection kit. Conclusions The fecal-like sample used in this Labquality’s EQA pilot study evaluates the complete analytical process including the preanalytical, analytical and postanalytical phases. An EQA scheme using this sample material is more compliant to ISO 15189 requirements compared to schemes where liquid or lyophilized samples are used. The new sample material used on this pilot study was positively received by most of the participants and it was compatible with all tests included in the study.

A-135 Assessment of Inter-Laboratory Variation in Biochemistry Parameters in Mongolian Clinical Laboratories: A Twelve-Year Analysis

Abstract Background External quality assessment (EQA) is essential for evaluating the performance of clinical laboratories and improving the quality of their analytical procedures. The Mongolian External Quality Assessment Scheme (MEQAS) has been established by organizations under the Ministry of Health to fulfill this purpose. The aim of this study is to provide a comprehensive summary of the inter-laboratory variation in biochemistry parameters among laboratories in Mongolia over a twelve-year period. Methods Three types of control materials were utilized: QAP-Trol Normal and Pathological levels, manufactured by Sysmex, and Pooled serum, prepared by combining leftover serum of patients. Samples were distributed semi-annually to laboratories, with participants measuring them promptly within three days. Results for 23 biochemistry parameters were submitted within a week via the “SmartEqas” software, enabling for analysis based on method and analyzer, and calculating standard deviation index (SDI), coefficient of variation (CV), and bias percentage (Bias%). Results In comparing the initial and most recent surveys, the number of participants has increased by nearly four times, rising from 55 to 217. Notably, the proportion of fully automatic users surged from 23.6% to 86.6%, a trend attributed to the establishment of numerous new laboratories and a growing recognition of the importance of EQA. Changes in the inter-laboratory coefficient of variation (CV) for each parameter were assessed from the initial to the recent period by calculating the mean of changes. In the recent assessments, CVs decreased to less than 10% for 14 parameters, including AST, ALT, UN, CRE, GLU, and others. Certain parameters, such as K, GLU, and Urea, exhibited markedly reduced variation from 16.3%, 12.1%, and 22.2% to 2.9%, 7.4%, and 9.3%, respectively. Conversely, some parameters, including LD (L-P), GGT, AMY (1), ALP (2), UA, TBIL, DBIL, FE, and MG, displayed gradual reductions in CVs to 10-20% compared to the initial period. In contrast, the coefficient of variation (CV) for four parameters: LD (P-L), AMY (2), ALP (3), and ALP (4), has not shown significant decreases and remains high, exceeding 20%. Conclusions Despite participation not being mandatory, laboratories in Mongolia exhibit a strong willingness to engage in the assessment process. The implementation of MEQAS has yielded tangible benefits, a reduction in inter-laboratory variation for most biochemistry parameters, with some achieving international level. While this improvement can be attributed to the streamlining of measurement methods, similar to outcomes observed in other countries, it is important to acknowledge the persistence of random and systematic errors. However, it is worth noting that certain parameters still exhibit higher CVs compared to similar studies. This discrepancy may be attributed to the inherent variation in enzymes among different methods and manufacturers. Hence, there is a clear need for continuous improvement measures and knowledge-sharing initiatives with other nations to address these challenges. Evaluating and implementing such measures at the national level will further enhance the quality of medical care in Mongolia.

B-215 Evaluating RT-qPCR for Dengue Virus Detection: Outcomes of a Brazilian External Quality Assessment Program

Abstract Background Dengue virus (DENV), responsible for a prevalent arthropod-borne viral illness, poses a substantial public health challenge worldwide. Clinically, DENV's manifestation often resembles that of other arboviruses, resulting in frequent healthcare visits and complicating the early diagnosis, which is critical for patient management. While virus isolation is a viable method, RT-qPCR assays yield significantly quicker results. Rapid immunochromatographic tests are available; yet, RT-qPCR not only matches their sensitivity but also provides distinct advantages in clinical laboratory settings. These include higher throughput and integrated, traceable quality control within each routine, offering less subjective and more dependable results. Maintaining high diagnostic standards for DENV is imperative. External quality assessment programs (EQAP) play a key role in enhancing laboratory diagnostic capabilities by monitoring and assessing diagnostic methods. This study evaluates the diagnostic efficacy of RT-qPCR for DENV using data from an EQAP conducted by a Brazilian provider, accredited by ABNT NBR ISO/IEC 17043:2011. Methods The quality control samples comprised lyophilized suspensions containing viable DENV particles, grown on vero cells (BCRJ 0245/ATCC CCL-81) under BSL-3 conditions. From February 2017 to November 2022, twenty-four EQAP survey rounds were carried out, each encompassing three samples, culminating in 1,153 data points. The evaluation metrics included participant numbers, adequacy percentage, sensitivity, specificity, and the incidence of false positives and negatives. The Mann-Kendall test assessed trends in these metrics over the survey rounds. The RT-qPCR kits employed by participants were classified either as in-vitro diagnostic (IVD) or as laboratory-developed tests (LDT). Kits that demonstrated high performance in terms of adequacy, sensitivity, and specificity were identified and listed. Results The number of laboratories participating has increased. Starting with four in 2017, the program expanded to 28 by 2022. Laboratory accuracy was high during the evaluation period, with a median of 99% (97.8% in 2017 and 99.2% in 2022). The Mann-Kendall test indicated a significant trend of increased accuracy (p&amp;lt;0.001). Specificity remained stable at 98.8%, while sensitivity improved, with a median of 99.4%—rising from 93.3% in 2017 to 100% in 2022 (p&amp;lt;0.001). Only three false negatives were reported over three separate rounds, and six false positives were reported across four rounds. Both LDT and IVD RT-qPCR kits demonstrated high accuracy (99.4% and 98.4%, respectively). Biomanguinhos ZDC, Viasure ZDC, and ZDC Multiplex kits all showed 100% adequacy, sensitivity, and specificity. Conclusions This study highlights the increasing adoption of RT-qPCR for DENV detection, as evidenced by the growing number of laboratories in the EQAP program and the consistently high adequacy rates from 2017 to 2022. Nonetheless, the number of participating laboratories remains relatively small for a vast tropical country like Brazil. The high sensitivity and specificity, along with the infrequency of false results, underscore its effectiveness. The superior performance of certain kits suggests possible advancements in DENV diagnosis, contributing to global public health initiatives against this arboviral disease.

B-212 Laboratory Performance in Molecular Detection of Mycobacterium tuberculosis Through Analysis of External Quality Assessment Program Results: WHO-Recommended Tests Outperform Others

Abstract Background In 2022, tuberculosis caused 11,200 deaths in Brazil and 1,300,000 globally. With 87,344 new cases, it remains a leading infectious cause of death, second only to COVID-19. Prompt detection is critical, particularly with the growing resistance to rifampicin and isoniazid, highlighting the need for molecular testing. External Quality Assessment Programs (EQAP) are essential to ensure the accuracy, reliability, and harmonization of laboratory results amid the complexities of M. tuberculosis infection. Here, we evaluate the overall performance of participating laboratories (labs) in three EQAP related to tuberculosis: M. tuberculosis molecular detection (MTB), Rifampicin resistance detection (RIF), and Isoniazid resistance detection (INH). All are organized by a Brazilian provider accredited according to the ABNT NBR ISO/IEC 17043:2011 standard. Methods The EQAP samples were suspensions containing human cells, with or without the addition of cultured, inactivated, and lyophilized M. tuberculosis. Labs received two samples quarterly for testing accuracy, sensitivity, and specificity. We computed these metrics along with participant and round numbers. The Mann-Kendall test assessed accuracy trends over time. Furthermore, kit type accuracies for in-vitro diagnostic (IVD) vs. laboratory-developed tests (LDT), World Health Organization recommended (WHO-recommended) vs. other kits (non-WHO), and methods (qPCR vs. PCR) were compared using chi-square tests and odds-ratio calculations. Results In the MTB EQAP (2018-2022), 63 labs participated over 20 rounds, with 22 (range: 6-48) labs per round on median, achieving 96.6% accuracy (853/883), 97.5% sensitivity (556/570), and 94.9% specificity (297/313). The Mann-Kendall test found no significant accuracy trends over time (τ = -0.91, p = 0.36). IVDs outperformed LDTs with 97.8% (751/768) vs. 87.9% (102/116) accuracy (OR=6.0, 95%CI 3.42-20.9, p&amp;lt;0.0001). WHO-recommended kits were more accurate than non-WHO kits, 98.2% (674/686) vs. 90.4% (179/198) (OR=5.96, 95%CI 1.05-12.7, p&amp;lt;0.0001). qPCR exceeded the accuracy of PCR, 97.2% (833/857) versus 74% (20/27) (OR=12.1, 95%CI 4.8-32.9, p&amp;lt;0.0001). For RIF EQAP (2020-2022), 49 laboratories in 9 rounds, with 25 (range: 18-42) laboratories per round on median, showed 97.4% accuracy (297/305), 97.2% sensitivity (176/181), and 97.6% specificity (121/124). In the INH EQAP (2021-2022), 7 laboratories over 7 rounds, with 4 (range: 2-5) laboratories per round on median, reached 95.2% accuracy (20/21), 100% sensitivity (4/4), and 94.1% specificity (16/17). Differences between types of kits and methods for RIF and INH, as well as trends over time, were not significant or could not be calculated due to the limited number of samples. Conclusions The MTB EQAP underscored the high participation and suitability of labs, along with excellent diagnostic performance; IVD kits were 6 times more likely to yield adequate results than LDTs. WHO-recommended kits were 5.9 times more likely to produce adequate results than non-WHO kits. qPCR was 12.6 times more likely to achieve adequate results than PCR. Despite fewer participants in RIF and INH, their performance rates were high; more data are needed for conclusive results on kit and method types. This study affirms the quality of molecular diagnostics for tuberculosis in Brazil, informs on kit and method selection, and underscores the critical role of EQAPs in combating a significant global health issue.

Workflow improvement and financial gain after integration of high-throughput sample processing system with flow cytometer in a high-volume pathology laboratory: Results from a prospective comparative study using Lean principles

BackgroundHighly efficient clinical laboratories are essential for monitoring many human illnesses. Ampath Laboratory Services, the largest pathology lab in South Africa, analyzes large numbers of peripheral blood samples for CD4 levels yearly. ObjectiveTo assess productivity and quality of a newer integrated automated solution, the BD FACSDuet™ Sample Preparation System/BD FACSLyric™ Flow Cytometer using conventional assessment methods and Lean concepts. Materials and methodsThis prospective study compared the performance of the BD FACS™ Sample Preparation Assistant [SPA] III and BD FACSCanto™ II Flow Cytometer with the newly introduced integrated system (BD FACSDuet™/BD FACSLyric™). They were validated for accuracy, precision, and external quality assessment. Process mapping and Lean assessment helped identify steps leading to waste. An economic model was developed to characterize workflow and economic impact associated with total daily hands-on time, processing time, and reworks. ResultsStrong linear correlation was present between both systems. Precision and accuracy studies revealed that all coefficient of variation (CV)% values were below 20 % of allowable limits. External proficiency assessments were within limits. The fully automated workflow of BD FACSDuet™/BD FACSLyric™ permitted better consistency with significantly shorter processing time and batch processing and reduced operator interventions. Lean assessment identified defects with motion, over-processing, waiting, and non-utilized talent. Significant reductions in hands-on and total daily processing time that could increase daily specimen testing efficiency and fewer reworks were associated with the BD FACSDuet™/BD FACSLyric™. Lean improvements translated to significant economic savings associated with operator costs and unnecessary reagent consumption. ConclusionBD FACSDuet™/BD FACSLyric™ is an accurate, reliable, and cost-effective fully automated system for high-volume flow cytometry labs that perform T-cell enumeration using a single-platform and single-tube approach.

Identification methods as a factor affecting the performance of clinical microbiology laboratories participating in an external quality assessment program: a cross-sectional, retrospective analysis.

Introduction. Laboratory participation in external quality assessment (EQA) programmes including proficiency testing (PT) is a requirement of clinical laboratory conformance to ISO 15189:2022 Medical laboratories - Requirements for quality and competence. PT is one EQA method whereby laboratories are sent blinded samples for characterization by routine laboratory diagnostic methods. Importantly, PT enables a laboratory's performance to be evaluated in comparison to the standard reference methods and to the performance of other peer laboratories using similar diagnostic methods.Gap statement. The desired outcome of participating in PT is to help laboratories identify possible sources of error in each step of the total testing process and particularly in their test methods during the analytical phase.Aim. This cross-sectional study investigated the impact of using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) compared to conventional phenotypic biochemical testing on laboratory performance in a clinical bacteriology PT scheme.Methodology. During a 6-year period from 2017-2022, the Canadian Microbiology Proficiency Testing implemented 112 PT challenges comprising 22 different sample types and included 61 different bacterial species. This was translated into 5883 graded test events for analysis. Multiple logistic regression techniques were employed to explore the association between the test method employed and laboratory performance. The sample type and aerobic classification of challenge organisms were included as confounding variables.Results. Laboratories using MALDI-TOF MS performed significantly better in characterizing microorganisms than laboratories using phenotypic biochemical testing alone [odds ratio OR = 5.68, confidence interval (CI): 3.92, 8.22] regardless of the sample type and aerobic classification. Notably, our analysis identified a significant association between anaerobic organisms and laboratory performance (OR: 0.24, CI: 0.17-0.35), suggesting that culturing and identifying fastidious organisms remains a significant obstacle for many clinical microbiology laboratories.Conclusions. Although no method is infallible and its performance will depend on the validation and quality assurance procedures, this finding may help the management in the decision for implementing MALDI-TOF MS in the microbiology laboratory. This study highlights the important role PT providers play in the objective assessment of laboratory performance and how it can provide evidence for quality improvement.