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313 result(s) for "Laboratory Proficiency Testing - standards"
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An 18-Year Review of Hemoglobinopathy Proficiency Testing: Recommendations From the College of American Pathologists Hematology and Clinical Microscopy Committee
The College of American Pathologists Hematology and Clinical Microscopy Committee implemented a hemoglobinopathy proficiency testing and education program to monitor and assess the performance of participating laboratories. To evaluate the performance of clinical laboratories for hemoglobinopathy proficiency testing from 2005 to 2023. The hemoglobinopathy challenges are composed of clinical case summaries and electrophoretic and chromatographic gel and tracing images. The participants are asked to determine (1) what hemoglobin chain is affected and (2) the hemoglobinopathy diagnosis. A total of 365 to 676 laboratories were enrolled in the proficiency testing program each year. Overall, the error rates for determination of the affected globin chain and a hemoglobinopathy diagnosis ranged from 0.6% to 56.5% and 0.5% to 86.5%, respectively. Twenty-three of 66 surveyed hemoglobinopathies (34.8%) had an error rate exceeding the consensus threshold of 20%. The globin gene detection error rate of the compound hemoglobinopathies was significantly higher when compared with just the α (P = .01) and β (P = .003) gene disorders. However, the error rate for the overall compound α/β-globin interpretation, although high at 23%, was not statistically significant when compared with just the α- or β-globin chain disorders. In repeat testing of the variants, there was no consistent improvement in performance. The program participants demonstrated variable performance with one-third of the surveys exceeding the 20% error rate. The error rate for compound hemoglobinopathies was even higher. Our data illustrate a critical need for continuing educational efforts with an algorithmic approach to hemoglobin disorders.
Towards harmonization of microscopy methods for malaria clinical research studies
Microscopy performed on stained films of peripheral blood for detection, identification and quantification of malaria parasites is an essential reference standard for clinical trials of drugs, vaccines and diagnostic tests for malaria. The value of data from such research is greatly enhanced if this reference standard is consistent across time and geography. Adherence to common standards and practices is a prerequisite to achieve this. The rationale for proposed research standards and procedures for the preparation, staining and microscopic examination of blood films for malaria parasites is presented here with the aim of improving the consistency and reliability of malaria microscopy performed in such studies. These standards constitute the core of a quality management system for clinical research studies employing microscopy as a reference standard. They can be used as the basis for the design of training and proficiency testing programmes as well as for procedures and quality assurance of malaria microscopy in clinical research.
Impact of Uniform Methods on Interlaboratory Antibody Titration Variability: Antibody Titration and Uniform Methods
Context.—Substantial variability between different antibody titration methods prompted development and introduction of uniform methods in 2008. Objective.—To determine whether uniform methods consistently decrease interlaboratory variation in proficiency testing. Design.—Proficiency testing data for antibody titration between 2009 and 2013 were obtained from the College of American Pathologists. Each laboratory was supplied plasma and red cells to determine anti-A and anti-D antibody titers by their standard method: gel or tube by uniform or other methods at different testing phases (immediate spin and/or room temperature [anti-A], and/or anti-human globulin [AHG: anti-A and anti-D]) with different additives. Interlaboratory variations were compared by analyzing the distribution of titer results by method and phase. Results.—A median of 574 and 1100 responses were reported for anti-A and anti-D antibody titers, respectively, during a 5-year period. The 3 most frequent (median) methods performed for anti-A antibody were uniform tube room temperature (147.5; range, 119–159), uniform tube AHG (143.5; range, 134–150), and other tube AHG (97; range, 82–116); for anti-D antibody, the methods were other tube (451; range, 431–465), uniform tube (404; range, 382–462), and uniform gel (137; range, 121–153). Of the larger reported methods, uniform gel AHG phase for anti-A and anti-D antibodies had the most participants with the same result (mode). For anti-A antibody, 0 of 8 (uniform versus other tube room temperature) and 1 of 8 (uniform versus other tube AHG), and for anti-D antibody, 0 of 8 (uniform versus other tube) and 0 of 8 (uniform versus other gel) proficiency tests showed significant titer variability reduction. Conclusion.—Uniform methods harmonize laboratory techniques but rarely reduce interlaboratory titer variance in comparison with other methods.
Test Cost and Test Accuracy in Clinical Laboratories in Kampala, Uganda
Abstract Objectives To assess the accuracy and costs of laboratory tests in Kampala, Uganda. Methods A random selection of 78 laboratories tested external quality assurance samples at market rates. There were 40 moderate- to high-complexity and 38 low-complexity laboratories. Four percent (3/78) of these laboratories were accredited and 94% (73/78) were private. The 40 moderate- to high-complexity laboratories performed malaria blood smear, urine human chorionic gonadotropin (hCG), human immunodeficiency virus (HIV), syphilis, glucose, and three-panel tests: CBC, liver function tests, and kidney function tests. The 38 low-complexity laboratories performed malaria blood smear, urine hCG, and syphilis testing only. Hematology, HIV, syphilis, and malarial proficiency testing samples were prepared by accredited laboratories in Kampala. All other samples were provided by the Royal College of Pathologists of Australia. Results 77.1% of all results were accurate (met target values). It varied widely by laboratory (50%-100%), test identity (malaria blood smear, 96%; serum urea nitrogen, 38%), and test type (quantitative: 66% [31%-89%], qualitative: 91% [68%-97%]). Test prices varied by up to 3,600%, and there was no correlation between test cost and accuracy (r2 = 0.02). Conclusions There were large differences in accuracy and price across laboratories in Kampala. Price was not associated with quality.
Prevalence of Traditional and Reverse-Algorithm Syphilis Screening in Laboratory Practice: A Survey of Participants in the College of American Pathologists Syphilis Serology Proficiency Testing Program
Context.—Syphilis serology screening in laboratory practice is evolving. Traditionally, the syphilis screening algorithm begins with a nontreponemal immunoassay, which is manually performed by a laboratory technologist. In contrast, the reverse algorithm begins with a treponemal immunoassay, which can be automated. The Centers for Disease Control and Prevention has recognized both approaches, but little is known about the current state of laboratory practice, which could impact test utilization and interpretation. Objective.—To assess the current state of laboratory practice for syphilis serologic screening. Design.—In August 2015, a voluntary questionnaire was sent to the 2360 laboratories that subscribe to the College of American Pathologists syphilis serology proficiency survey. Results.—Of the laboratories surveyed, 98% (2316 of 2360) returned the questionnaire, and about 83% (1911 of 2316) responded to at least some questions. Twenty-eight percent (378 of 1364) reported revision of their syphilis screening algorithm within the past 2 years, and 9% (170 of 1905) of laboratories anticipated changing their screening algorithm in the coming year. Sixty-three percent (1205 of 1911) reported using the traditional algorithm, 16% (304 of 1911) reported using the reverse algorithm, and 2.5% (47 of 1911) reported using both algorithms, whereas 9% (169 of 1911) reported not performing a reflex confirmation test. Of those performing the reverse algorithm, 74% (282 of 380) implemented a new testing platform when introducing the new algorithm. Conclusion.—The majority of laboratories still perform the traditional algorithm, but a significant minority have implemented the reverse-screening algorithm. Although the nontreponemal immunologic response typically wanes after cure and becomes undetectable, treponemal immunoassays typically remain positive for life, and it is important for laboratorians and clinicians to consider these assay differences when implementing, using, and interpreting serologic syphilis screening algorithms.
CAP/ACMG proficiency testing for biochemical genetics laboratories: a summary of performance
Testing for inborn errors of metabolism is performed by clinical laboratories worldwide, each utilizing laboratory-developed procedures. We sought to summarize performance in the College of American Pathologists’ (CAP) proficiency testing (PT) program and identify opportunities for improving laboratory quality. When evaluating PT data, we focused on a subset of laboratories that have participated in at least one survey since 2010. An analysis of laboratory performance (2004 to 2014) on the Biochemical Genetics PT Surveys, a program administered by CAP and the American College of Medical Genetics and Genomics. Analytical and interpretive performance was evaluated for four tests: amino acids, organic acids, acylcarnitines, and mucopolysaccharides. Since 2010, 150 laboratories have participated in at least one of four PT surveys. Analytic sensitivities ranged from 88.2 to 93.4%, while clinical sensitivities ranged from 82.4 to 91.0%. Performance was higher for US participants and for more recent challenges. Performance was lower for challenges with subtle findings or complex analytical patterns. US clinical biochemical genetics laboratory proficiency is satisfactory, with a minority of laboratories accounting for the majority of errors. Our findings underscore the complex nature of clinical biochemical genetics testing and highlight the necessity of continuous quality management.
Quantification of histochemical stains using whole slide imaging: development of a method and demonstration of its usefulness in laboratory quality control
Aims Histochemical staining of tissue is a fundamental technique in tissue diagnosis and research, but it suffers from significant variability. Efforts to address this include laboratory quality controls and quality assurance schemes, but these rely on subjective interpretation of stain quality, are laborious and have low reproducibility. We aimed (1) to develop a method for histochemical stain quantification using whole slide imaging and image analysis and (2) to demonstrate its usefulness in measuring staining variation. Methods A method to quantify the individual stain components of histochemical stains on virtual slides was developed. It was evaluated for repeatability and reproducibility, then applied to control sections of an appendix to quantify H&E staining (H/E intensities and H:E ratio) between automated staining machines and to measure differences between six regional diagnostic laboratories. Results The method was validated with <0.5% variation in H:E ratio measurement when using the same scanner for a batch of slides (ie, it was repeatable) but was not highly reproducible between scanners or over time, where variation of 7% was found. Application of the method showed H:E ratios between three staining machines varied from 0.69 to 0.93, H:E ratio variation over time was observed. Interlaboratory comparison demonstrated differences in H:E ratio between regional laboratories from 0.57 to 0.89. Conclusions A simple method using whole slide imaging can be used to quantify and compare histochemical staining. This method could be deployed in routine quality assurance and quality control. Work is needed on whole slide imaging devices to improve reproducibility.
Marked Variability in Reported Minimal Residual Disease Lower Level of Detection of 4 Hematolymphoid Neoplasms: A Survey of Participants in the College of American Pathologists Flow Cytometry Proficiency Testing Program
Flow cytometry is often applied to minimal residual disease (MRD) testing in hematolymphoid neoplasia. Because flow-based MRD tests are developed in the laboratory, testing methodologies and lower levels of detection (LODs) are laboratory dependent. To broadly survey flow cytometry laboratories about MRD testing in laboratories, if performed, including indications and reported LODs. Voluntary supplemental questions were sent to the 549 laboratories participating in the College of American Pathologists (CAP) FL3-A Survey (Flow Cytometry-Immunophenotypic Characterization of Leukemia/Lymphoma) in the spring of 2014. A total of 500 laboratories (91%) responded to the supplemental questions as part of the FL3-A Survey by April 2014; of those 500 laboratories, 167 (33%) currently perform MRD for lymphoblastic leukemia, 118 (24%) for myeloid leukemia, 99 (20%) for chronic lymphocytic leukemia, and 91 (18%) for plasma cell myeloma. Other indications include non-Hodgkin lymphoma, hairy cell leukemia, neuroblastoma, and myelodysplastic syndrome. Most responding laboratories that perform MRD for lymphoblastic leukemia reported an LOD of 0.01%. For myeloid leukemia, chronic lymphocytic leukemia, and plasma cell myeloma, most laboratories indicated an LOD of 0.1%. Less than 3% (15 of 500) of laboratories reported LODs of 0.001% for one or more MRD assays performed. There is major heterogeneity in the reported LODs of MRD testing performed by laboratories subscribing to the CAP FL3-A Survey. To address that heterogeneity, changes to the Flow Cytometry Checklist for the CAP Laboratory Accreditation Program are suggested that will include new requirements that each laboratory (1) document how an MRD assay's LOD is measured, and (2) include the LOD or lower limit of enumeration for flow-based MRD assays in the final diagnostic report.
Results of the UK NEQAS for Molecular Genetics reference sample analysis
AimsIn addition to providing external quality assessment (EQA) schemes, United Kingdom National External Quality Assessment service (UK NEQAS) for Molecular Genetics also supports the education of laboratories. As an enhancement to the Molecular Pathology EQA scheme, a human cell-line reference sample, manufactured by Thermo Fisher Scientific (AcroMetrix), was provided for analysis. This contained many variants, present at frequencies between 1% and 17.9%.MethodsOne hundred and one laboratories submitted results, with a total of 2889 test results on 53 genes being reported. Known polymorphisms, 46/2889 (1.59%) results, were excluded. Variants detected in the seven most commonly reported (and clinically relevant) genes, KRAS, NRAS, BRAF, EGFR, PIK3CA, KIT and PDGFRA, are reported here, as these genes fall within the scope of UK NEQAS EQA schemes.ResultsNext generation sequencing (NGS) was the most commonly performed testing platform. There were between 5 and 27 validated variants in the seven genes reported here. Eight laboratories correctly reported all five NRAS variants, and two correctly reported all eight BRAF variants. The validated mean variant frequency was lower than that determined by participating laboratories, with single-gene testing methodologies showing less variation in estimated frequencies than NGS platforms. Laboratories were more likely to correctly identify clinically relevant variants.ConclusionsOver 100 laboratories took the opportunity to test the ‘educational reference sample’, showing a willingness to further validate their testing platforms. While it was encouraging to see that the most widely reported variants were those which should be included in routine testing panels, reporting of variants was potentially open to interpretation, thus clarity is still required on whether laboratories selectively reported variants, by either clinical relevance or variant frequency.