1
|
Cherie N, Deress T, Berta DM, Chane E, Teketelew BB, Adane K, Nigus M. Navigating Quality Assessment Hurdles in Clinical Laboratory Services: A Comprehensive Review in Resource-Limited Settings. Risk Manag Healthc Policy 2024; 17:497-504. [PMID: 38476199 PMCID: PMC10929212 DOI: 10.2147/rmhp.s453020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
External quality assessment is the process of evaluating the performance of a laboratory and the competence of professionals. Participation in EQA and standardizing the quality of laboratory services are a mandatory requirements for accreditation. This review is aimed at identifying and discussing challenges that hinder the effective implementation of an EQA program in countries with resource limited setting. To obtain abundant information, articles were identified by searching the literature publishedin English using the National Library of Medicine, PubMed, Science Direct and AMC digital library databases. The articles identified in the references were manually searched and included. After the article was identified, it was imported to Endnote version 8.1 and exported to Microsoft Word for citation. Based on this review, the major identified challenges that hinder the implementation of an EQA program include the high cost of control materials, malfunction and lack of maintenance for equipment failure and breakdown, a knowledge gap among laboratory professionals, noncommutability of control samples, and difficulty in assigning target values. In addition, failing to participate in EQA and failing to take corrective action are the major challenges identified. As a result, applying to an EQA program in resource-limited counties was highly challenging. To attain high performance in the laboratory and to provide quality laboratory service for patient care, the EQA supplier and the user laboratory must pay attention to these issues and take appropriate corrective actions for ongoing quality improvement and accreditation.
Collapse
Affiliation(s)
- Negesse Cherie
- Department of Quality Assurance and Laboratory Management, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Teshiwal Deress
- Department of Quality Assurance and Laboratory Management, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Dereje Mengesha Berta
- Department of Hematology and Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Elias Chane
- Department of Clinical Chemistry, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Bisrat Birke Teketelew
- Department of Hematology and Immunohematology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Kasaw Adane
- Department of Quality Assurance and Laboratory Management, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Mesele Nigus
- Department of Quality Assurance and Laboratory Management, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| |
Collapse
|
2
|
Ricós C, Fernández-Calle P, Perich C, Sandberg S. Control externo de la calidad en medicina del laboratorio. Avances y futuro. ADVANCES IN LABORATORY MEDICINE 2022; 3:232-242. [PMCID: PMC10197501 DOI: 10.1515/almed-2022-0059] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/20/2022] [Indexed: 12/29/2023]
Abstract
Objectivos Un programa de control externo distribuye las mismas muestras control entre varios laboratorios y evalúa los resultados obtenidos con un criterio común. El objetivo de este trabajo es resumir la evolución de los programas externos, poner de manifiesto los progresos conseguidos y deducir consecuencias prácticas para el laboratorio participante. Métodos El material es una breve revisión de los diferentes tipos de programas externos utilizados a lo largo de cuarenta años. El método es el análisis crítico de las ventajas e inconvenientes de cada modelo, a la luz de nuestra experiencia. Resultados A mitad del siglo XX se iniciaron los programas EQA, detectándose gran discrepancia entre resultados emitidos por distintos laboratorios. Se desarrollaron EQA en muchos países y se propusieron mecanismos para armonizarlos, como: establecer especificaciones derivadas de la variación biológica, promover el uso de métodos analíticos homogéneos, usar el EQA como herramienta educacional. A partir del 2000 se hacen importantes avances: asegurar el adecuado uso clínico de las pruebas del laboratorio, utilizar material control conmutable con el espécimen humano, armonizar los distintos modelos de EQA, promover una organización de cooperación entre organizadores de programas EQA. Conclusiones Participar en un EQA con controles conmutables y valores asignados por método de referencia certificado permite conocer la inexactitud real de los resultados y el impacto en las muestras de pacientes. Si se participa en programas con controles no conmutables solo se conoce si la prestación del laboratorio es similar a la de otros usuarios del mismo método analítico.
Collapse
Affiliation(s)
- Carmen Ricós
- Sociedad Española de Medicina del Laboratorio (SEQC), Barcelona, España
| | - Pilar Fernández-Calle
- Sociedad Española de Medicina del Laboratorio (SEQC), Barcelona, España
- Departamento de Medicina del Laboratorio, Hospital Universitario La Paz, Madrid, España
| | - Carmen Perich
- Sociedad Española de Medicina del Laboratorio (SEQC), Barcelona, España
| | - Sverre Sandberg
- Organización noruega para la mejora de la calidad de los exámenes del laboratorio (NOKLUS), Hospital Universitario Haukeland, Bergen, Norway
| |
Collapse
|
3
|
Ricós C, Fernández-Calle P, Perich C, Sandberg S. External quality control in laboratory medicine. Progresses and future. ADVANCES IN LABORATORY MEDICINE 2022; 3:221-242. [PMID: 37362144 PMCID: PMC10197337 DOI: 10.1515/almed-2022-0058] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/30/2022] [Indexed: 06/28/2023]
Abstract
Objectives An external quality control program distributes same control samples to various laboratories and evaluates results obtained with a common criterion. The aim of this work is to summarize the evolution of various types of external programs, to point out the progresses ant to preclude practical consequences of the participant laboratories. Content The material consists on a brief revision of the different types of external programs that have been used for the last forty years. The method is the critical analysis of the strong and weak points of each program model, from the light of our experience. External quality assessment (EQA) programs were initiated at half the XX century, evidencing big discrepancies among laboratory results. EQA were developed in various countries and some mechanisms to harmonize them were proposed: to establish common performance specifications derived from biological variation, to use EQS as educational tool. Since the 2000 important advances were seen: to focus EQA to assure the adequate clinical use of laboratory tests, to use commutable controls, to harmonize the different EQA models, to promote a forum for co-operation and exchange of knowledge on quality-related matters for EQA organizers. Summary and Outlook To participate in an EQA with commutable-reference method assigned values controls allows to know the real inaccuracy of results and their impact on patient' samples. To participate in a EQA with non commutable controls allows to know whether the individual laboratory performance agrees with that from other laboratories using same analytical method.
Collapse
Affiliation(s)
- Carmen Ricós
- Sociedad Española de Medicina del Laboratorio (SEQC), Barcelona, Spain
| | - Pilar Fernández-Calle
- Sociedad Española de Medicina del Laboratorio (SEQC), Barcelona, Spain
- Departamento de Medicina del Laboratorio, Hospital Universitario La Paz, Madrid, Spain
| | - Carmen Perich
- Sociedad Española de Medicina del Laboratorio (SEQC), Barcelona, Spain
| | - Sverre Sandberg
- Norwegian Organization for Quality Improvement of Laboratory Examinations (NOKLUS), Hospital Universitario Haukeland, Bergen, Norway
| |
Collapse
|
4
|
Montalvão SADL, Lowe A, Kitchen S. Advantages of external quality assessment-EQA programs. Haemophilia 2022; 28:679-686. [PMID: 35415926 DOI: 10.1111/hae.14562] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/24/2022] [Accepted: 03/24/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The first external quality assessment (EQA) in Thrombosis and Haemostasis was elaborated over 20 years ago, and since then, several national and international EQA institutions have been established. AIM Display the benefits of EQA programs. METHODS The spectrum of EQA action was evaluated ranges from improving the performance of the local laboratory to highlighting inadequate diagnostic tests that need to be replaced by new technologies. RESULTS The first result approach is related to a national management of quality in laboratories. In recent years, Brazil has invested in an EQA program to aid public policy in the laboratory area. During this period, a group of haemostasis laboratory specialists were invited to manage the results and help the Ministry of Health with applying these results as a strategy to improve laboratories. Thus, in collaboration with NEQAS-BC, the University of Campinas - UNICAMP, established a Brazilian EQA program for Blood Coagulation. The second result approach is related to FVIII inhibitor assay performance evaluation, which is another type of EQA program benefit. Despite the assay being considered the gold standard to measure neutralised immunoglobulins for FVIII since 1975, over 40 years ago, the test still has a high coefficient of variation. Results from NEQAS-BC and WFH IEQAS program demonstrate the inter-laboratory variation across the United Kingdom over the last years and among emergent countries. CONCLUSION The EQA programs have an important educational role in helping countries manage their public policy and in the international inquiry regarding the necessity of new technologies in haemostasis.
Collapse
Affiliation(s)
| | - Anna Lowe
- UK NEQAS Blood Coagulation, Sheffield, UK
| | | |
Collapse
|
5
|
Kouri T, Fogazzi G, Gant V, Hallander H, Hofmann W, Guder WG. European Urinalysis Guidelines. Scandinavian Journal of Clinical and Laboratory Investigation 2019. [DOI: 10.1080/00365513.2000.12056993] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
6
|
Honour JW. Standardization of steroid tests and implications for the endocrine community: Author’s reply. Ann Clin Biochem 2018; 55:410. [DOI: 10.1177/0004563218762542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
7
|
Stavelin A, Albe X, Meijer P, Sarkany E, MacKenzie F. An overview of the European Organization for External Quality Assurance Providers in Laboratory Medicine (EQALM). Biochem Med (Zagreb) 2017; 27:30-36. [PMID: 28392724 PMCID: PMC5382863 DOI: 10.11613/bm.2017.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/24/2016] [Indexed: 11/18/2022] Open
Abstract
The European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM) was founded in 1996 and currently has members from 29 European countries and 6 countries from outside Europe. EQALM provides a forum for co-operation and exchange of knowledge on quality-related matters in laboratory medicine, especially with regard to external quality assessment (EQA) programs in Europe. In addition, EQALM represent the EQA providers in laboratory medicine at European level vis-ŕ-vis political, professional, scientific and other bodies, including patients’ organisations. To this end EQALM promotes activities such as organizing meetings with scientific and practical themes for members and other interested parties, issuing scientific publications, developing EQA projects and representing laboratory medicine EQA activities within other organisations and networks. EQALM is active in scientific and educational activity in different fields such as survey frequency, haematology, haemostasis, microbiology, nomenclature, virtual microscopy, traceability, accreditation, and quality assurance of the total testing process. The aim of this paper is to give an overview of the EQALM organisation.
Collapse
Affiliation(s)
- Anne Stavelin
- The Norwegian Quality Improvement of Primary Care Laboratories (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
| | - Xavier Albe
- Swiss Center for Quality Control (CSCQ), Chęne-Bourg, Switzerland
| | - Piet Meijer
- External quality Control for Assays and Tests with a focus on Thrombosis and Haemostasis (ECAT Foundation), Voorschoten, The Netherlands
| | - Erika Sarkany
- In Vitro Diagnostic Quality Control (QualiCont), Szeged, Hungary
| | - Finlay MacKenzie
- United Kingdom National External Quality Assessment Service (UK NEQAS) for Clinical Chemistry, Institute of Research and Development, University Hospitals Birmingham, UK
| |
Collapse
|
8
|
Kristensen GBB, Meijer P. Interpretation of EQA results and EQA-based trouble shooting. Biochem Med (Zagreb) 2017; 27:49-62. [PMID: 28392726 PMCID: PMC5382861 DOI: 10.11613/bm.2017.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/24/2016] [Indexed: 11/03/2022] Open
Abstract
Important objectives of External Quality Assessment (EQA) is to detect analytical errors and make corrective actions. The aim of this paper is to describe knowledge required to interpret EQA results and present a structured approach on how to handle deviating EQA results. The value of EQA and how the EQA result should be interpreted depends on five key points: the control material, the target value, the number of replicates, the acceptance limits and between lot variations in reagents used in measurement procedures. This will also affect the process of finding the sources of errors when they appear. The ideal EQA sample has two important properties: it behaves as a native patient sample in all methods (is commutable) and has a target value established with a reference method. If either of these two criteria is not entirely fulfilled, results not related to the performance of the laboratory may arise. To help and guide the laboratories in handling a deviating EQA result, the Norwegian Clinical Chemistry EQA Program (NKK) has developed a flowchart with additional comments that could be used by the laboratories e.g. in their quality system, to document action against deviations in EQA. This EQA-based trouble-shooting tool has been developed further in cooperation with the External quality Control for Assays and Tests (ECAT) Foundation. This flowchart will become available in a public domain, i.e. the website of the European organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM).
Collapse
Affiliation(s)
| | - Piet Meijer
- ECAT Foundation (External quality Control for Assays and Tests), Netherlands
| |
Collapse
|
9
|
Weykamp C, Wielders J, Helander A, Anton RF, Bianchi V, Jeppsson JO, Siebelder C, Whitfield JB, Schellenberg F. Harmonization of Measurement Results of the Alcohol Biomarker Carbohydrate-Deficient Transferrin by Use of the Toolbox of Technical Procedures of the International Consortium for Harmonization of Clinical Laboratory Results. Clin Chem 2014; 60:945-53. [DOI: 10.1373/clinchem.2014.221531] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
BACKGROUND
The need for equivalent results of routine measurement procedures for the alcohol biomarker carbohydrate-deficient transferrin (CDT) has been recognized by the IFCC. This article describes a project to harmonize CDT as conducted by an IFCC working group initiated for this purpose.
METHODS
We used procedures for achieving harmonization as developed by the Consortium for Harmonization of Clinical Laboratory Results to assess the suitability of a candidate reference measurement procedure (cRMP), candidate reference materials (cRMs), and the success of efforts to achieve harmonization.
RESULTS
CDT measurement procedures in routine use showed good reproducibility (CV 1.1%–2.8%) and linearity (r > 0.990) with variable slopes (0.766–1.065) and intercepts (−0.34 to 0.92) compared to the cRMP. Heterogeneity after simulated harmonization was 4.7%. cRMs of frozen human native sera demonstrated commutability and 3-year stability for routine measurement procedures. The cRMP provided reproducible value assignment to cRMs with an expanded uncertainty (k = 2) of 0.03% at the 1.2% CDT level and 0.06% at the 4.4% CDT level. Harmonization efforts reduced the intermeasurement CV from 8.8% to 3.4%, allowed 99% recovery of the values assigned with the cRMP, and demonstrated 99% of results within the desirable allowable total error. Harmonization was less successful in samples with low CDT and high trisialotransferrin concentrations.
CONCLUSIONS
Harmonization of CDT is possible with frozen human native sera as cRMs with values assigned by use of the cRMP. We propose the cRMP as a candidate international conventional reference measurement procedure and cRMs as candidate international calibrators.
Collapse
Affiliation(s)
- Cas Weykamp
- Department of Clinical Chemistry, Queen Beatrix Hospital, Winterswijk, the Netherlands
| | - Jos Wielders
- Department of Clinical Chemistry, Meander Medical Center, Amersfoort, the Netherlands
| | - Anders Helander
- Department of Laboratory Medicine, Karolinska Institutet, and Karolinska University Laboratory, Clinical Chemistry, Stockholm, Sweden
| | - Raymond F Anton
- The Center for Drug and Alcohol Programs, Medical University of South Carolina, Charleston, SC
| | - Vincenza Bianchi
- Toxicology Reference Laboratory, SS. Antonio e Biagio Hospital, Alessandria, Italy
| | - Jan-Olof Jeppsson
- Department of Laboratory Medicine, Malmö University Hospital, Malmö, Sweden
| | - Carla Siebelder
- Department of Clinical Chemistry, Queen Beatrix Hospital, Winterswijk, the Netherlands
| | | | | |
Collapse
|
10
|
Stepman HCM, Tiikkainen U, Stöckl D, Vesper HW, Edwards SH, Laitinen H, Pelanti J, Thienpont LM. Measurements for 8 common analytes in native sera identify inadequate standardization among 6 routine laboratory assays. Clin Chem 2014; 60:855-63. [PMID: 24687951 DOI: 10.1373/clinchem.2013.220376] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND External quality assessment (EQA) with commutable samples is essential for assessing the quality of assays performed by laboratories, particularly when the emphasis is on their standardization status and interchangeability of results. METHODS We used a panel of 20 fresh-frozen single-donation serum samples to assess assays for the measurement of creatinine, glucose, phosphate, uric acid, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. The commercial random access platforms included: Abbott Architect, Beckman Coulter AU, Ortho Vitros, Roche Cobas, Siemens Advia, and Thermo Scientific Konelab. The assessment was done at the peer group level and by comparison against the all-method trimmed mean or reference method values, where available. The considered quality indicators were intraassay imprecision, combined imprecision (including sample-matrix interference), bias, and total error. Fail/pass decisions were based on limits reflecting state-of-the-art performance, but also limits related to biological variation. RESULTS Most assays showed excellent peer performance attributes, except for HDL- and LDL cholesterol. Cases in which individual assays had biases exceeding the used limits were the Siemens Advia creatinine (-4.2%), Ortho Vitros phosphate (8.9%), Beckman Coulter AU triglycerides (5.4%), and Thermo Scientific Konelab uric acid (6.4%), which lead to considerable interassay discrepancies. Additionally, large laboratory effects were observed that caused interlaboratory differences of >30%. CONCLUSIONS The design of the EQA study was well suited for monitoring different quality attributes of assays performed in daily laboratory practice. There is a need for improvement, even for simple clinical chemistry analytes. In particular, the interchangeability of results remains jeopardized both by assay standardization issues and individual laboratory effects.
Collapse
Affiliation(s)
- Hedwig C M Stepman
- Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | | | | | - Hubert W Vesper
- Centers for Disease Control and Prevention (CDC), Division of Laboratory Sciences, Atlanta, GA
| | - Selvin H Edwards
- Centers for Disease Control and Prevention (CDC), Division of Laboratory Sciences, Atlanta, GA
| | | | | | - Linda M Thienpont
- Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium;
| | | |
Collapse
|
11
|
Jamtsho R. Stability of lyophilized human serum for use as quality control material in bhutan. Indian J Clin Biochem 2014; 28:418-21. [PMID: 24426247 DOI: 10.1007/s12291-013-0328-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 04/09/2013] [Indexed: 10/26/2022]
Abstract
Quality control (QC) materials are crucial for internal quality control (IQC) and external quality assessment scheme (EQAS). However, many developing countries are disadvantaged by unavailability and high cost of commercial control material. Therefore, preparing home-made lyophilized human serum will be cost effective for used as a QC material in Bhutan. We prepared lyophilized QC material using serum collected from Bhutanese volunteers. The stability of lyophilized serum was studied at 3 selected conditions by analyzing at certain intervals. The results were statistically compared with initial values. The significant p values (<0.05) were seen in glucose, BUN, ALT, total bilirubin and protein at 2-8 °C but no significant difference were observed at -20 °C at the end of 9 months. We concluded that, home-made lyophilized human serum prepared without stabilizers could be used at least up to 9 months if stored at -20 °C and 7 months at 2-8 °C. Stabilizers and additives are necessary if the materials are to be used longer than 7-9 months.
Collapse
Affiliation(s)
- Rixin Jamtsho
- Department of Laboratory Medicine, Jigme Dorji Wangchuk National Referral Hospital, Thimphu, Bhutan
| |
Collapse
|
12
|
Paleari R, Muñoz A, Mosca A. Towards the development of a certified reference material for hemoglobin A2. Clin Chem Lab Med 2010; 48:1611-8. [DOI: 10.1515/cclm.2010.317] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
13
|
Commutability of NIST SRM 1955 Homocysteine and Folate in Frozen Human Serum with selected total homocysteine immunoassays and enzymatic assays. Clin Chim Acta 2008; 395:99-105. [PMID: 18565331 DOI: 10.1016/j.cca.2008.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 05/16/2008] [Accepted: 05/21/2008] [Indexed: 11/24/2022]
Abstract
BACKGROUND The National Institute of Standards and Technology (NIST) has recently developed Standard Reference Material (SRM) 1955 Homocysteine and Folate in Frozen Human Serum with certified values for total homocysteine (tHcy) and 5-methyl-tetrahydrofolic acid. NIST has performed an international, interlaboratory assessment of SRM 1955 commutability; results are reported for tHcy only. METHODS Total Hcy was measured in 20 patient sera and in 3 levels of SRM 1955 using 14 immunoassays and/or enzymatic assays. Liquid chromatography/tandem mass spectrometry was utilized as the reference assay. An "errors-in-variables" statistical model was utilized to assess the commutability of SRM 1955. RESULTS Normalized residuals ranged from -2.65 to 2.19 for SRM 1955. The median interlaboratory/interassay imprecision (CV) was approximately 4% for patient specimens and ranged from approximately 3% to approximately 7% for SRM 1955. The median intra-assay imprecision ranged from approximately 1% to approximately 13%. Orthogonal residuals, as a descriptor of assay accuracy, ranged from 0.29 to 7.71 and from 0.20 to 2.22 for patient specimens and SRM 1955 samples, respectively. CONCLUSION The current study suggests that SRM 1955 is commutable with the investigated tHcy assays; however, a broader specimen set needs to be evaluated to completely substantiate this conclusion.
Collapse
|
14
|
Dominici R, Cabrini E, Cattozzo G, Ceriotti F, Grazioli V, Scapellato L, Franzini C. Intermethod variation in serum carcinoembryonic antigen (CEA) measurement. fresh serum pools and control materials compared. Clin Chem Lab Med 2002; 40:167-73. [PMID: 11939491 DOI: 10.1515/cclm.2002.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study was undertaken to evaluate the feasibility of using commercial control materials in a regional external quality assessment scheme (EQAS) for serum carcinoembryonic antigen (CEA) measurement. We have assessed the commutability of 12 commercial control materials using five automated immunochemical systems. We compared the intermethod behavior of the materials with that of 12-14 patient serum pools. In a total of 48 comparisons (12 materials x 4 pairs of analytical systems), seven instances of non-commutability were apparent, as shown by normalized residuals falling outside the +/-3 interval. The use of non-commutable materials generates two negative effects. In EQAS, the interlaboratory variation recorded is not representative of the variation expected in the assay of patient sera; in interlaboratory harmonization programs, recalibration with non-commutable materials increases, instead of decreasing, the interlaboratory variation. Both these effects were shown to occur in CEA measurement with the tested materials and systems. The materials planned to be used in our EQAS turned out to be commutable: this gave us the guarantee of measuring realistic interlaboratory variation values, although the check for commutability should be extended to all the analytical systems used by the participants in the scheme.
Collapse
Affiliation(s)
- Roberto Dominici
- Istituto di Scienze Biomediche Ospedale L. Sacco, Università degli Studi di Milano, Italy
| | | | | | | | | | | | | |
Collapse
|
15
|
Sciacovelli L, Secchiero S, Zardo L, Plebani M. External Quality Assessment Schemes: need for recognised requirements. Clin Chim Acta 2001; 309:183-99. [PMID: 11438299 DOI: 10.1016/s0009-8981(01)00521-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Programs for Accreditation of clinical laboratories consider participation in External Quality Assessment Schemes (EQAS) a key element in the evaluation of testing procedures and improving them. One of the main functions of EQAS is to assess whether laboratories perform tests competently. It is therefore of utmost importance for laboratories to participate in EQAS that are in line with formally recognised requirements. Specific proposals have been made on how to design and execute EQAS by International Working Groups, but there seems to be no consensus on the best strategies to use and quality specifications to set out. The Clinical Pathology Accreditation (CPA) Program for EQA Scheme Accreditation (CPA-EQA) is the only program in Europe to provide a formal recognition of the quality of EQAS activities. The present paper reports on the experience of the Centre of Biomedical Research which is following an accreditation process for their own schemes in line with the CPA-EQA program and a proposal to set requirements that Italian schemes must follow to be recognised as valid and effective.
Collapse
Affiliation(s)
- L Sciacovelli
- Centro di Ricerca Biomedica, Via Ospedale, 18, 31033 Castelfranco Veneto, Treviso, Italy.
| | | | | | | |
Collapse
|
16
|
Cattozzo G, Franzini C, d'Eril GV. Myoglobin and creatine kinase isoenzyme MB mass assays: intermethod behaviour of patient sera and commercially available control materials. Clin Chim Acta 2001; 303:55-60. [PMID: 11163023 DOI: 10.1016/s0009-8981(00)00370-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The low biological variation of myoglobin and creatine kinase isoenzyme MB mass (CK-MBm) requires accurate measurements. In the standardization process, in order to effectively measure and correct intermethod variability, the intermethod behaviour of control materials must be the same of patient sera, i.e. they must be commutable. In this work we checked the commutability of some commercially available control materials in pairs of methods for myoglobin and CK-MBm measurements; we assessed the impact of commutable and non-commutable control materials when used for equalizing patient sera results by two different methods and discussed the problems related to external quality assessment schemes. Myoglobin and CK-MBm were measured in sets of 49 and 56 patient sera and in 13 commercially available control materials with two automatic analytical systems. The non-commutability rate was 8.3% for myoglobin and 23.1% for CK-MBm. Recalculation of serum samples results with a control material as calibrator lowered or increased the bias originally present according to whether the material itself was commutable or not. We conclude that also for myoglobin and CK-MBm assays it is necessary to check the commutability of materials to be used in external quality assessment schemes, or to normalize patient results by different methods.
Collapse
Affiliation(s)
- G Cattozzo
- Laboratorio di Analisi, Ospedale F. Del Ponte-A. O. Fondazione Macchi, Via F. Del Ponte, 19, 21100 Varese, Italy.
| | | | | |
Collapse
|
17
|
Cattozzo G, Scarsi G, Franzini C. Normalizing intermethod free triiodothyronine patient results: need for commutable materials. Clin Chem Lab Med 1998; 36:777-80. [PMID: 9853805 DOI: 10.1515/cclm.1998.138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this work was to check the suitability of control materials to normalize intermethod results for the measurement of free triiodothyronine in patient sera. In the main experiment, 108 patient sera and 11 commercially available control materials were assayed by a pair of methods. In a confirmatory experiment, two of the control materials and 142 patient sera were assayed with an alternative pair of methods. In the main experiment, the intermethod variability of 6/11 control materials differed significantly from that of patient sera (i. e. control materials were non-commutable). Recalculation of patient results using control materials as calibrators lowered the intermethod difference only if commutable materials were used. The confirmatory experiment demonstrated that the pattern of commutability changed if a different pair of methods was used. We conclude that in the case of free triiodothyronine the commutability of control materials should be tested if they are to be used to normalize patient results obtained by different methods.
Collapse
Affiliation(s)
- G Cattozzo
- Laboratorio di Analisi, Ospedale C. Ondoli, Angera (VA), Italia
| | | | | |
Collapse
|