scholarly journals Optimization of Storage Medium for Hematological Reference Samples in External Quality Assessment

2021 ◽  
Vol 11 (18) ◽  
pp. 8777
Author(s):  
Ngoc Nguyen Vo ◽  
Huu Tam Tran ◽  
Quan Thuy Truong ◽  
Thuy Huong Nguyen
Keyword(s):  
Quality Assessment ◽  
Blood Cells ◽  
External Quality Assessment ◽  
White Blood Cells ◽  
Theoretical Data ◽  
External Quality ◽  
Factors Affecting ◽  
Human Red Blood Cells ◽  
Reference Samples ◽  
Optimal Formula

Hematological reference samples for external quality assessment (EQA) in hematology are essential for many laboratories in Vietnam, however, the prices are high along with short storing time. This study attempted to establish an optimal formula for the manufacture of hematological reference samples for hematological EQA programs. Human red blood cells (RBCs) were mixed with goose RBCs (pseudo-leucocytes) and goat RBCs (pseudo-platelets) as alternatives for white blood cells (WBCs) and platelets (PLTs), respectively, in different formulas of storage media. The optimal formula was obtained using response surface methodology–central composite design (RSM-CCD). Three main factors affecting the concentrations of RBCs were determined by Plackett–Burmann matrix. The optimal concentrations determined by RSM-CCD were 46% serum, 0.44 g/L neomycin sulfate, and 2.5% glycerol. The model predicted that the maximum number of human RBCs was 4.1 × 1012 cells/L, pseudo-leucocytes was 6.4 × 109 cells/L, and pseudo-platelets was 188 × 109 cells/L. The practical concentrations of RBCs, pseudo-leucocytes, and pseudo-platelets were 4.21 × 1012 cells/L, 6.4 × 109 cells/L, and 187 × 109 cells/L, respectively, which showed 98.93% similarity with theoretical data. This result could be a premise for further study to improve manufacturing of hematological reference samples for hematology EQA programs.

A new approach to define acceptance limits for hematology in external quality assessment schemes

2017 ◽  
Vol 55 (12) ◽  
Author(s):  
Mohamed Rida Soumali ◽  
Marjan Van Blerk ◽  
Abdelhadi Akharif ◽  
Stéphanie Albarède ◽  
Dagmar Kesseler ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Blood Cells ◽  
External Quality Assessment ◽  
White Blood Cells ◽  
External Quality ◽  
Assigned Value ◽  
Evaluation Procedures ◽  
Survey Results ◽  
Acceptance Limits ◽  
Relative Differences

Abstract:Background:A study performed in 2007 comparing the evaluation procedures used in European external quality assessment schemes (EQAS) for hemoglobin and leukocyte concentrations showed that acceptance criteria vary widely. For this reason, the Hematology working group from the European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM) decided to perform a statistical study with the aim of establishing appropriate acceptance limits (AL) allowing harmonization between the evaluation procedures of European EQAS organizers.Methods:Eight EQAS organizers from seven European countries provided their hematology survey results from 2010 to 2012 for red blood cells (RBC), hemoglobin, hematocrit, mean corpuscular volume (MCV), white blood cells (WBC), platelets and reticulocytes. More than 440,000 data were collected. The relation between the absolute value of the relative differences between reported EQA results and their corresponding assigned value (U-scores) was modeled by means of an adaptation of Thompson’s “characteristic function”. Quantile regression was used to investigate the percentiles of the U-scores for each target concentration range. For deriving AL, focus was mainly on the upper percentiles (90th, 95th and 99th).Results:For RBC, hemoglobin, hematocrit and MCV, no relation was found between the U-scores and the target concentrations for any of the percentiles. For WBC, platelets and reticulocytes, a relation with the target concentrations was found and concentration-dependent ALs were determined.Conclusions:The approach enabled to determine state of the art-based ALs, that were concentration-dependent when necessary and usable by various EQA providers. It could also easily be applied to other domains.

External quality assessment of urine particle identification: a Northern European experience

2015 ◽  
Vol 53 (s2) ◽  
Author(s):  
Timo T. Kouri ◽  
Pirjo Makkonen
Keyword(s):  
Epithelial Cells ◽  
Quality Assessment ◽  
Blood Cells ◽  
External Quality Assessment ◽  
White Blood Cells ◽  
Particle Identification ◽  
Added Value ◽  
External Quality ◽  
Morphological Findings ◽  
Future Technologies

AbstractExternal quality assessment (EQA) schemes for urinalysis have been provided by Labquality Ltd, the publicly owned EQA service provider in Finland, since the 1980s. In 2014, the scheme on urine particle identification had 329 participating laboratories, out of which 60% from 19 countries were outside Finland. Each of the four annual web-based rounds were distributed with four Sternheimer-stained images from a single patient sample, as viewed both by bright-field and phase-contrast optics. Participants reported classified categories either at the basic or at the advanced level. Participating laboratories received assessment of their analytical performance as compared to their peers, including reflections from clinical data and preanalytical detail of the specimen. In general, reporting of basic urine particles succeeded in the eight schemes during the years 2013–2014 as follows: red blood cells 82%–92%, white blood cells 82%–97%, squamous epithelial cells 92%–98%, casts 84%–94%, and small epithelial cells 73%–83% (minimum and maximum of expected or accepted reports). This basic level of differentiation is used in routine laboratory reports, or as verification of results produced by automated instruments. Considerable effort is needed to standardise national procedures and reporting formats, in order to improve the shown figures internationally. Future technologies may help to alleviate limitations created by single digital images. Despite improvements, degenerating cells and casts always exhibit intermediate forms creating disputable classifications. That is why assessment of performance should encompass justified acceptable categories into the assessed outcomes. Preanalytical and clinical detail provide essential added value to morphological findings.

Digital Imaging - a Web Based Exercise for Blood Cell and Bone Marrow Morphology as Part of a National Quality Assesment Scheme.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5301-5301
Author(s):  
Emma Wells ◽  
John Ardern ◽  
Michelle Brereton ◽  
Lois Hickman ◽  
John Burthem ◽  
...  
Keyword(s):  
Image Quality ◽  
Blood Cell ◽  
Quality Assessment ◽  
Digital Imaging ◽  
Blood Cells ◽  
Digital Images ◽  
External Quality Assessment ◽  
External Quality ◽  
Consensus Opinion ◽  
Static Images

Abstract Over the last four years we have undertaken a development program in collaboration with the UK National External Quality Assessment Scheme for Haematology NEQAS(H) to use internet-based teaching and digital photography to improve consensus opinion on haematological cellular morphology. We began with providing participants with a series of individual images of haematological blood cells to most recently, multiple ‘stitched’ images with tutorial based feedback on cell type and diagnosis. We present the results from a fourth internet-based blood cell morphology exercise. Participants were invited to visit the Central Manchester Laboratory website (www.manlab.co.uk) or the UKNEQAS (H) website to review a series of digital photographic images of blood cells. Volunteers to the exercise were able to call up images from a previously reported haematology case with complex morphology and report on their findings. Digital images were presented in three formats. The first provided twelve static images with expert morphological comment and participant’s consensus comments from the original national survey. The second part provided four static images with an interactive tutorial clearly identifying specific cell types and morphology of interest. The third component was a composite of nine individual images ‘Stitched’ together that allowed movement across the image and a zoom facility. Of 426 participants 128 (30%) returned results to UK NEQAS (H). Part 1: Over 90% of responders gave positive opinion regarding image quality, access to the website, presentation of expert opinion and agreed that the single images appropriately represented the morphological features of the case. Part 2: Over 95% responded positively to the educational value of the tutorial. Part 3: Of 128 responders, 34 were unable to download the software necessary to view the ‘Stitched’ image due their Trust’s internet policy. Of the remaining 94 responders, 90% found the image quality adequate and representative. A high proportion (71%) thought the ease of navigation and magnification offered by the Stitched image offered advantages over single static images and provided a better overview of morphology. The positive feedback from this exercise supports our intention to place digital images of the six annual UK NEQAS(H) blood film surveys on the internet. The problems of downloading stitched imaging software are to be addressed and there is ongoing development of stitching 40–100 single images into a virtual slide. A key role for external quality assessment schemes is to provide an educational service. The digital imaging procedure offers the opportunity to provide tutorial based learning to highlight interesting morphology and build up consensus opinion. The educational aspect of this is creating much interest and will provide a mechanism for continuing professional development of scientific and medical staff.

Analysis and evaluation of the external quality assessment results of quality indicators in laboratory medicine all over China from 2015 to 2018

2019 ◽  
Vol 57 (6) ◽  
pp. 812-821 ◽  
Author(s):  
Min Duan ◽  
Fengfeng Kang ◽  
Haijian Zhao ◽  
Wei Wang ◽  
Yuxuan Du ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Quality Indicators ◽  
External Quality Assessment ◽  
External Quality ◽  
Factors Affecting ◽  
Laboratory Errors ◽  
Continuous Quality ◽  
Clinical Laboratories ◽  
Information Construction ◽  
Quality Specifications

Abstract Background This study aimed to comprehensively evaluate laboratory quality in China and explore factors affecting laboratory errors through analyzing the external quality assessment (EQA) results of quality indicators (QIs). Methods According to model 3 (interpretive) of the proficiency testing scheme, the National Center for Clinical Laboratories of China (CNCCL) developed a questionnaire for 15 QIs. Clinical laboratories from different provinces of China participated in the EQA program of QIs annually and submitted data via an online reporting system named Clinet-EQA. The results of QIs were expressed in percentage and sigma value or minute. Three levels of quality specifications (QSs) were defined based on percentile values. Furthermore, the QIs were analyzed by disciplines, hospital scales and information construction levels of participant laboratories. Results A total of 3450 laboratories nationwide continuously attended the EQA program and submitted complete data from 2015 to 2018. The performance of most QIs has improved year by year. QIs in post-analytical gained the best performance with sigma values that varied from 5.3σ to 6.0σ. The comparison of results among different disciplines showed significant differences for five QIs. More than half of QIs had statistical differences among different hospital scales measured by hospital grades and number of hospital beds. The performance of nine QIs were influenced by information construction levels of participant laboratories. Conclusions The overall laboratory quality in China has improved since the initiation of EQA program for QIs, but the performance of some QIs was still unsatisfactory. Therefore, laboratories should make efforts for continuous quality improvement based on information provided by QSs.

scholarly journals The versatility of external quality assessment for the surveillance of laboratory and in vitro diagnostic performance: SARS-CoV-2 viral genome detection in Austria

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christoph Buchta ◽  
Jeremy V. Camp ◽  
Jovana Jovanovic ◽  
Peter Chiba ◽  
Elisabeth Puchhammer-Stöckl ◽  
...  
Keyword(s):  
Quality Assessment ◽  
External Quality Assessment ◽  
False Negative ◽  
Positive Sample ◽  
Performance Criteria ◽  
External Quality ◽  
Assay Sensitivity ◽  
Dilution Series ◽  
Test Systems

Abstract Objectives External quality assessment (EQA) schemes provide information on individual and general analytical performance of participating laboratories and test systems. The aim of this study was to investigate the use and performance of SARS-CoV-2 virus genome detection systems in Austrian laboratories and their preparedness to face challenges associated with the pandemic. Methods Seven samples were selected to evaluate performance and estimate variability of reported results. Notably, a dilution series was included in the panel as a measure of reproducibility and sensitivity. Several performance criteria were evaluated for individual participants as well as in the cohort of all participants. Results A total of 109 laboratories participated and used 134 platforms, including 67 different combinations of extraction and PCR platforms and corresponding reagents. There were no false positives and 10 (1.2%) false negative results, including nine in the weakly positive sample (C t ∼35.9, ∼640 copies/mL). Twenty (22%) laboratories reported results of mutation detection. Twenty-five (19%) test systems included amplification of human RNA as evidence of proper sampling. The overall linearity of C t values from individual test systems for the dilution series was good, but inter-assay variability was high. Both operator-related and systematic failures appear to have caused incorrect results. Conclusions Beyond providing certification for participating laboratories, EQA provides the opportunity for participants to evaluate their performance against others so that they may improve operating procedures and test systems. Well-selected EQA samples offer additional inferences to be made about assay sensitivity and reproducibility, which have practical applications.

Commutability of possible external quality assessment materials for progesterone measurement

2021 ◽  
Vol 87 ◽  
pp. 39-45
Author(s):  
Xilian Yi ◽  
Yufei Wang ◽  
Tianjiao Zhang ◽  
Jie Zeng ◽  
Haijian Zhao ◽  
...  
Keyword(s):  
Quality Assessment ◽  
External Quality Assessment ◽  
External Quality
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