External Quality Assessment Research Articles

Sensitivity Assessment of a Multiplex and Real-Time PCR Protocols for the Detection of Malaria in External Quality Control Samples in the Malaria Reference Center in Greece

Background: Accurate malaria diagnosis constitutes a challenging task, necessitating the need for the implementation of targeted and effective diagnostic tools. The purpose of the current study was to evaluate the effectiveness of two different molecular methodologies in terms of sensitivity for the detection of External Quality Assessment (EQA) Plasmodium samples. Methods: A total of 104 lyophilized blood samples from 14 different UK-NEQAS (National External Quality Assessment Site) (2016–2021) and eight WHO-NEQAS distributions (2017–2020) were analyzed. An in-house multiplex PCR protocol, followed by single target real-time PCR protocols for all five Plasmodium species, was implemented. Results: The multiplex PCR had a success rate of 10/16 and 20/28 for P. vivax and P. falciparum species, respectively. On the other hand, the respective results for real-time PCR had a success rate of 13/16 (P. vivax), 28/28 (P. falciparum), 5/8 (P. malariae), 8/10 (P. ovale), and 10/14 (P. knowlesi). Plasmodium falciparum samples displayed the highest sensitivity of detection, 0.02 parasites/μL. Plasmodium vivax samples displayed a 0.1 parasites/μL cutoff value, greater than the respective value for whole blood samples, while P. ovale species displayed a respective cutoff value of 0.05 parasites/μL. Due to the limited number of tested samples, data obtained for P. malariae and P. knowlesi species samples were inconclusive. Conclusions: Real-time PCR comprises a credible molecular methodology in terms of sensitivity assessment and detection of low parasitemia levels of Plasmodium sp. in EQA lyophilized blood samples.

External quality assessment schemes in bacteriology support public health in Germany-results from 2006 to 2023.

External Quality Assessment schemes (EQAS) are mandatory to ensure quality standards in diagnostic methods and achieve laboratory accreditation. As host institution for two German culture-based bacteriology EQAS (RV-A and RV-B), we investigated the obtained data of 590 up to 720 surveys per year in RV-A and 2,151 up to 2,929 in RV-B from 2006 to 2023. As educational instruments, they function to review applied methodology and are valuable to check for systemic- or method-dependent failures in microbiology diagnostics or guidelines. Especially, containment of multi-resistant bacteria in times of rising antibiotic resistance is one major point to assure public health. The correct identification and reporting of these strains is therefore of high importance to achieve this goal. Moreover, correct antimicrobial susceptibility testing (AST) per se is important for selecting appropriate therapy, to restrict broad-spectrum antibiotics and minimize resistance development. The reports of participating laboratories displayed a high level of correct identification results in both schemes with mostly consistent failure rates around 2.2% (RV-A) and 3.9% (RV-B) on average. In contrast, results in AST revealed increasing failure rates upon modification of AST requirements concerning adherence to standards and subsequent bacterial species-specific evaluation. Stratification on these periods revealed in RV-A a moderate increase from 1.3% to 4.5%, while in RV-B failure rates reached 14% coming from 4.3% on average. Although not mandatory, subsequent AST evaluation and consistent reporting are areas of improvement to benefit public health.

New statistical framework for interlaboratory evaluation of anti-doping testing results by WADA

The World Anti-doping Agency (WADA) International Standard for Laboratories (ISL), developed as part of the World Anti-Doping Program, requires satisfactory laboratory performance in the WADA External Quality Assessment Scheme (EQAS) in order to obtain and maintain WADA accreditation. Under this mandate, WADA regularly distributes urine and blood test samples to anti-doping laboratories to continuously monitor their proficiency. Over the years, WADA has employed classical, generic statistical methods, in accordance to ISO 13528, to evaluate quantitative EQAS results. Here, we set out the rationale for a modern statistical approach that recognizes and addresses the particular features of the measurement results typically obtained in such tests and present an approach involving Bayesian measurement models and statistical data analysis that is tailored specifically to anti-doping testing.

External care quality assessment in residential care facilities for the elderly: ethical challenges and needs for clarification with a focus on ethics consultation

External care quality assessment in residential care facilities for the elderly: ethical challenges and needs for clarification with a focus on ethics consultation

Evaluating proficiency testing implementation and identifying challenges that government comprehensive specialized hospital laboratories in northwest Ethiopia faced as they participated in the external quality assessment scheme: A document-based, interview-driven evaluation.

To assess the implementation of proficiency testing in the northwest Ethiopian government comprehensive specialized hospital laboratories, with a focus on identifying and understanding the challenges encountered during their participation in the external quality assessment scheme. A cross-sectional study was conducted among 3 comprehensive specialized hospitals in northwest Ethiopia, analyzing 41 documented laboratory test parameters from 2020 to 2022. In addition, face-to-face, in-depth interviews were carried out to identify the major challenges the participating institutions faced. The study covered a total of 41 tests across 9 cycles. Overall, proper implementation of proficiency testing was observed in 59.3% of the tests, with 61.8% maintaining consistent implementation status over 3 consecutive years. In addition, the overall performance of the laboratory was 54.3%, with a 68.7% participation rate. The predominantly identified challenges included the lack of participation, insufficient reagents and supplies, inadequacy of suitable proficiency testing materials, equipment malfunction and downtime, lack of management support, insufficient budget, and inadequate training and awareness. The results of this study highlight the ineffective implementation of proficiency testing. Contributing factors include personnel issues, equipment and supplies challenges, managerial shortcomings, difficulties with proficiency testing providers, budgetary constraints, and a lack of training and motivation.

Development and implementation of the external quality assessment program for erythrocyte sedimentation rate in hematology laboratories in Thailand

Background: The erythrocyte sedimentation rate (ESR) remains the most widely used screening test for monitoring the course of infections, inflammatory diseases, and some types of cancer. Proficiency Testing (PT) programs are unavailable in Thailand for ESR. Objective: This study aimed to develop and initiate the PT program to improve testing quality through evaluation and analysis of the laboratory test results for ESR. Materials and methods: The PT program for ESR was established at the AMS CMU EQA Unit by the ISO/IEC17043:2010 requirements. The unit produced and sent the ESR control materials to participants for laboratory analysis; the test results were returned to the unit. The PT program was carried out in two cycles per year, with two samples in each cycle. The performance of each laboratory was assessed using robust Z score and performance score. Results: ESR control materials presented with satisfactory homogeneity and stability according to ISO 13528: 2015. One hundred and four laboratories were enrolled in the PT program. Of these laboratories, 96 (92.3%) returned their data: 40 (42.7%) used the modified Westergren method, 29 (29.2%), 14 (15.7%), and 13 (12.4%) used Microsed, Mixrate, and other methods, respectively. Satisfactory and questionable performance was obtained in 82/96 (85.4.%) and 8/96 (8.3%), respectively. Unsatisfactory performance was noted at 6/96 (6.3%). The level of excellent performance was achieved by 82 (approx. 85%) of these laboratories. Two main types of errors found from analyzing the received data were (i) specimen processing and (ii) incorrect identification of the analytical method. Conclusion: Our results indicate that the advantage of participation in the PT program for ESR is that the laboratories can monitor and investigate the source of laboratory errors. Therefore, the PT program for ESR testing should become an integral part of the quality assurance system in the laboratory.

Abstract PO5-26-09: Digital image analysis and a novel set of cell line samples as aids in the development of a quantitative external quality assessment programme for Ki-67

Abstract Background and Aims Ki-67 is a well-established biomarker of proliferation in breast cancer (BC). However, its value in treatment decision making is hampered by a lack of analytical reproducibility. Regular participation in external quality assessment (EQA) substantially improves inter-laboratory concordance. Pre-requisites in establishing a fit-for-purpose EQA for Ki-67 are a well-validated testing substrate and a reproducible method of assessing Ki-67 scores in participants’ submitted materials. We report here on the results of work using cell line controls analysed by digital image analysis (DIA) as a first step towards providing such an EQA. Materials and Methods A formalin-fixed paraffin embedded (FFPE) cell line microarray (CLMA) was designed and produced in conjunction with Array Sciences LLC (Sausalito, USA). It was comprised of cores taken from a pure population of Sf9 caterpillar cells, which have been shown to be completely unreactive with most commercial antibodies to human Ki-67, together with cores of Sf9 cells mixed with four different human BC cell lines. These were BT-20 (85% BC cells), ZR-75-1 (75%), BT-474 (65%) and BT-483 (55%). Sections from the CLMA were mounted onto glass microscope slides together with sections from a FFPE tonsil sample and two BC samples; one BC showed high (~30%, BC-high) and the second, low proliferation (~5%, BC-low). In both BC samples proliferating cancer cells were distributed homogeneously throughout the the block. Unstained sections were distributed to laboratories participating in the Scheme’s Ki-67 BC programme; after routine IHC-staining for Ki-67 returned slides were centrally visually assessed for stain quality and subjected to DIA using an in-house application developed on Visiopharm software (Visiopharm A/S, Hoersholm, Denmark). Results Slides were returned by 37 laboratories. Analysis of Ki-67 scores obtained on the Sf9 core identified two distinct groups. The first (n = 27) were negative or showed low Ki-67 scores (mean = 1.1%, 95% CIs: 0.2-1.9%), the second (n = 10) displayed a step-change in scores (mean = 49.9%, 95% CIs: 33.2-66.7%); the means of the two groups were significantly different (P< 0.0001). When Ki-67 scores for each of the tissue samples were dichotomized into similar groups, the means of those groups differed significantly for the two BC samples (P< 0.001), but not for tonsil. Quality scores generated by visual assessment did not differ significantly between the two groups. However, when slides bearing Sf9 cores demonstrating aberrant Ki-67 scores were visually examined nuclear staining was clearly visible, and non-specific nuclear staining could also be identified in the matched BC tissue samples, but not in the tonsil sections. Correlation of Ki-67 scores between the four BC cell line cores and each of the BC tissue samples was examined using Pearson’s correlation statistics. The r statistic range was 0.57-0.71 in comparisons between BC cell line cores and the BC-high sample, and 0.53-0.70 for those with BC-low; in each case BT-483 showed the highest correlation score and BT-20 the lowest. A similar analysis was undertaken between the tonsil and the two BC tissues. The r statistic for correlation between tonsil and BC-high scores was 0.72; it was 0.64 for those between tonsil and BC-low. Conclusions By using a pure population of Sf9 cells we have developed a sensitive indicator of non-specific nuclear staining in IHC preparations stained for Ki-67 which identifies the presence of the artefact quantifiably. Cores made from Sf9/BC cell line mixtures (especially BT-483) produce Ki-67 scores which correlate with those obtained in breast cancer samples at a similar level to those achieved between tonsil and BC samples; this is true for both high and the low proliferation ranges. Cell line mixtures can be adjusted to show Ki-67 scores in the clinically relevant ranges, and they do not show the inherent biological variations seen in tissue controls such as tonsil. Citation Format: Andrew Dodson, Fitim Berisha, Dawn Wilkingson, Lila Zabaglo, Suzanne Parry. Digital image analysis and a novel set of cell line samples as aids in the development of a quantitative external quality assessment programme for Ki-67 [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-26-09.

Measurement uncertainty in clinical chemistry: ISO 20914 versus nordtest or intermediate precision versus bias

Aim Measuring uncertainty (MU) is crucial to ensure the accuracy and precision of laboratory results. This study compares the ISO 20914 and Nordtest guidelines to analyze the MU values for 20 clinical chemistry analytes over six months. Methods The researchers calculated MU components, including within-laboratory reproducibility (Rw), laboratory analytical performance bias (u(bias)), and combined standard uncertainty (u c), based on internal quality control and external quality assessment data. The final expanded uncertainty (U) values were determined by multiplying the combined uncertainty with a coverage factor (k = 2 for 95% Confidence Interval), following each guideline’s respective procedures. Clinical chemistry analytes were analyzed on Roche Cobas 6000 c501 auto analyzer (Roche Diagnostics, Mannheim, Germany) and manufacturer’s kits were used analysis. Results The results show that 11 out of 20 clinical chemistry analytes met the targeted maximum allowable measurement uncertainty (MAU) values when calculated according to ISO 20914 guideline. Also, 11 out of 20 clinical chemistry analytes’ MU values met the MAU values with the Nordtest guideline’s recommended calculations. However, some tests met the MAU in the ISO 20914 approach but not in the Nordtest guideline, and vice versa. Conclusions The study found that intermediate precision (u Rw) in the ISO 20914 approach and performance bias (u(bias)) in the Nordtest approach significantly impacted MU values. The research highlights the importance of standardization in MU calculation approaches across clinical laboratories. These findings have implications for patient care and clinical decision-making, emphasizing the importance of selecting appropriate laboratory guidelines for routine use.

A review of performance on the Weqas quantitative faecal haemoglobin (FIT) external quality assessment (EQA) programme – Are current analysers ‘FIT’ for purpose?

A review of performance on the Weqas quantitative faecal haemoglobin (FIT) external quality assessment (EQA) programme – Are current analysers ‘FIT’ for purpose?

A review of lactate performance on the weqas blood gas external quality assessment (EQA) programme – A comparison of POCT and lab instruments and their suitability for use in sepsis management

A review of lactate performance on the weqas blood gas external quality assessment (EQA) programme – A comparison of POCT and lab instruments and their suitability for use in sepsis management

Results of the external quality assessment (EQA) scheme for serological diagnostic test for SARS-CoV-2 detection in Sicily region (Italy), in 2020–2022

Results of the external quality assessment (EQA) scheme for serological diagnostic test for SARS-CoV-2 detection in Sicily region (Italy), in 2020–2022

A seven-year experience of external quality assessment program for Kleihauer-Betke test

A seven-year experience of external quality assessment program for Kleihauer-Betke test

Results of 2023 national external quality assessment of blood gases, electrolytes and metabolites testing in medical laboratories of the Republic of Belarus

Results of 2023 national external quality assessment of blood gases, electrolytes and metabolites testing in medical laboratories of the Republic of Belarus

An improved implementation of metrological traceability concepts is needed to benefit from standardization of laboratory results.

Non-harmonization of laboratory results represents a concrete risk for patient safety. To avoid harms, it is agreed that measurements by in vitro diagnostic medical devices (IVD-MD) on clinical samples should be traceable to higher-order references and adjusted to give the same result. However, metrological traceability is not a formal claim and has to be correctly implemented, which in practice does not happen for a non-negligible number of measurands. Stakeholders, such as higher-order reference providers, IVD manufacturers, and External Quality Assessment organizers, have major responsibilities and should improve their contribution by unambiguously and rigorously applying what is described in the International Organization for Standardization 17511:2020 standard and other documents provided by the international scientific bodies, such as Joint Committee on Traceability in Laboratory Medicine and IFCC. For their part, laboratory professionals should take responsibility to abandon non-selective methods and move to IVD-MDs displaying proper selectivity, which is one of the indispensable prerequisites for the correct implementation of metrological traceability. The practicality of metrological traceability concepts is not impossible but relevant education and appropriate training of all involved stakeholders are essential to obtain the expected benefits in terms of standardization.

Evaluating laboratory performance in Dengue virus detection by using RT-qPCR: Analysis of a Brazilian external quality assessment program results

Evaluating laboratory performance in Dengue virus detection by using RT-qPCR: Analysis of a Brazilian external quality assessment program results

Results of 2023 national external quality assessment of hemostasis testing in medical laboratories of the Republic of Belarus

Results of 2023 national external quality assessment of hemostasis testing in medical laboratories of the Republic of Belarus

Brazilian external quality assessment program for serum total cholesterol – A report from 2007 TO 2023

Brazilian external quality assessment program for serum total cholesterol – A report from 2007 TO 2023

The Italian external quality assessment program for Cystic Fibrosis sweat chloride test: CFTR modulators and the impact of a new sweat test report form

BackgroundThe advent of CFTR modulators highlighted that the sweat test (ST) for CF can be used also as an outcome measure for the basic defect of CFTR. Despite the technological advances, ST still remains operator-dependent and its execution should be strongly paired with guidelines. In 2022, due to the advent of CFTR modulators, the Italian CF Society introduced a specific ST report. The aim of the present paper is to discuss the impact of this new report in the 2022-23 round of the Italian External Quality Assessment program for ST (I-EQA-SCT). MethodsThe scheme of the I-EQA-SCT is prospective, enrolment is voluntary, the payment of a fee is required and results are shared through a web-facility. Assessment covers analysis, interpretation, and reporting of results. In the 2022-23 round, 2 out of the 3 mock clinical information referred to patients who started modulators. ResultsFourteen laboratories completed the 2022-23 I-EQA-SCT round. Three of them failed in the interpretation of results from these two mock cases and/or used a wrong report not consistent with the more recent Italian Sweat Test Recommendations. ConclusionsThe overall results obtained from the laboratories involved in the I-EQA-SCT program clearly showed that the laboratories’ qualitative and quantitative performance improved significantly. Results emerged from this round highlighted an issue in the report form used for monitoring patients on CFTR modulator therapy thus stressing the importance of these programs in improving both the performance of lab services and ameliorating the sweat test recommendations.

Effect of bilirubin assays on treatment decision in neonatal jaundice: Past and present using Dutch external quality assessment results

Effect of bilirubin assays on treatment decision in neonatal jaundice: Past and present using Dutch external quality assessment results

Brazilian external quality assessment program for serum TSH and free T4 – A report from 2007 to 2023

Brazilian external quality assessment program for serum TSH and free T4 – A report from 2007 to 2023