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Shipkova M, Wieland E, Schütz E. Toward Analytical Performance Specifications for Immunosuppressive Drug Quantification in Transplantation: An Opinion Article. Ther Drug Monit 2024:00007691-990000000-00269. [PMID: 39357035 DOI: 10.1097/ftd.0000000000001261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Accepted: 08/14/2024] [Indexed: 10/04/2024]
Abstract
BACKGROUND Analytical methods require performance that meets the clinical needs. Different approaches for setting up permissible analytical imprecision goals (pCVA%) for drug analyses have been reported. The aim of this study was to calculate the pCVA% for cyclosporine, tacrolimus, everolimus, sirolimus, and mycophenolic acid using 4 alternative approaches, to compare the results and to critically discuss advantages and disadvantages of each model. METHODS The approaches to evaluate pCVA% were (A) based on biological variation observed in routine measurement results between 2022 and 2023 in the authors' laboratory, (B) derived from the terminal elimination half-life and dosing interval of the drugs, and (C and D) explored from the width of the therapeutic ranges (TR) by the 2 methods. For approach A, routine measurement data for cyclosporine and tacrolimus, obtained through liquid chromatography-tandem mass spectrometry and electrochemiluminescence immunoassays, were evaluated separately. RESULTS The 4 alternative approaches for deriving pCVA% yielded similar results, for cyclosporine and tacrolimus in an analytical method dependent manner. The average pCVA% was 5.2%, 5.6%, 5.1%, 4.8%, and 7.7% for cyclosporine, tacrolimus, everolimus, sirolimus, and mycophenolic acid, respectively. The most challenging goals were those using TR-related approaches, while those using the biological variation approach were most easily achievable. Approach B resulted in more stringent goals for drugs with longer elimination half-lives (eg, everolimus and sirolimus). CONCLUSIONS There is no single ideal approach for setting goals of drug analysis. However, the pCVA% values derived from the various approaches are similar and confirm that a <6% target proposed by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology is adequate and realistic in combination with state-of-the-art measurement technologies. In the authors' opinion, approaches based on the width of the TR are preferable, as they represent a common basis for clinical decisions and reflect elements of biological variation and analytics used to establish the TR.
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Affiliation(s)
- Maria Shipkova
- Bioscientia Institut für Medizinische Diagnostik, Ingelheim, Germany; and
| | - Eberhard Wieland
- Bioscientia Institut für Medizinische Diagnostik, Ingelheim, Germany; and
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2
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Hoffmann G, Klawitter S, Trulson I, Adler J, Holdenrieder S, Klawonn F. A Novel Tool for the Rapid and Transparent Verification of Reference Intervals in Clinical Laboratories. J Clin Med 2024; 13:4397. [PMID: 39124664 PMCID: PMC11313426 DOI: 10.3390/jcm13154397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/10/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024] Open
Abstract
Background/Objectives: We present a software package called reflimR (Version 1.0.6), which enables rapid and transparent verification of reference intervals from routine laboratory measurements. Our method makes it easy to compare the results with specified target values and facilitates the interpretation of deviations using traffic light colors. Methods: The algorithm includes three procedural steps: (a) definition of an appropriate distribution model, based on Bowley's quartile skewness, (b) iterative truncation, based on a modified boxplot method to obtain the central 95% of presumably inconspicuous results, and (c) extrapolation of reference limits from a truncated normal quantile-quantile plot. Results: All algorithms have been combined into one consolidated library, which can be called in the R environment with a single command reflim (x). Using an example dataset included in the package, we demonstrate that our method can be applied to mixed data containing a substantial proportion of pathological values. It leads to similar results as the direct guideline approach as well as the more sophisticated indirect refineR software package. As compared to the latter, reflimR works much faster and needs smaller datasets for robust estimates. For the interpretation of the results, we present an intuitive color scheme based on tolerance ranges (permissible uncertainty of laboratory results). We show that a relatively high number of published reference limits require careful reevaluation. Conclusions: The reflimR package closes the gap between direct guideline methods and the more sophisticated indirect refineR method. We recommend reflimR for the rapid routine verification of large amounts of reference limits and refineR for a careful analysis of unclear or doubtful results from this check.
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Affiliation(s)
- Georg Hoffmann
- German Heart Center, Institute of Laboratory Medicine, Technical University Munich, 80636 Munich, Germany
- Trillium GmbH Medizinischer Fachverlag, 82284 Grafrath, Germany
| | - Sandra Klawitter
- Trillium GmbH Medizinischer Fachverlag, 82284 Grafrath, Germany
- Institute for Information Engineering, Ostfalia University of Applied Sciences, 38302 Wolfenbüttel, Germany
| | - Inga Trulson
- German Heart Center, Institute of Laboratory Medicine, Technical University Munich, 80636 Munich, Germany
| | - Jakob Adler
- Institut für Hämostaseologie und Pharmakologie (IHP), 12247 Berlin, Germany
- Institut für Medizinische Diagnostik (IMD), 12247 Berlin, Germany
| | - Stefan Holdenrieder
- German Heart Center, Institute of Laboratory Medicine, Technical University Munich, 80636 Munich, Germany
| | - Frank Klawonn
- Institute for Information Engineering, Ostfalia University of Applied Sciences, 38302 Wolfenbüttel, Germany
- Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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3
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Manzocchi S, van Rooyen LJ. Are analytical performance specifications derived from reference intervals of any use in the veterinary clinical laboratory? A preliminary study on the empirical biological variation model. Vet Clin Pathol 2024; 53 Suppl 1:86-95. [PMID: 38238987 DOI: 10.1111/vcp.13317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 10/09/2023] [Accepted: 10/29/2023] [Indexed: 02/22/2024]
Abstract
BACKGROUND Analytical performance specifications (APS) are vital for method evaluation and quality control validation. However, the limited availability of biological variation (BV) data, regulatory guidelines, and expert opinion (EO) may present challenges in veterinary medicine. The empirical biological variation (EBV) approach, based on population reference intervals (pRI), has emerged as an alternative method to derive APS in human medicine. OBJECTIVES This study aimed to assess the practicality and usefulness of the EBV approach in deriving performance limits for various measurands in dogs and cats. METHODS Eight hematology and 13 biochemistry measurands were analyzed in dogs and cats. Estimates of combined biologic variation based on traditional biological (CVB ) and EBV-derived (CVE *) formulas were calculated and assessed for evidence of correlation. Performance limits for expanded uncertainty/total error and imprecision were compared among EO, BV, and EBV. RESULTS Strong and significant correlations were found between CVB and CVE * for both dogs (r = .86, p < .00001) and cats (r = 0.95, p < .00001). The EBV-derived APS were generally comparable to EO and BV, with a subjective criterion of 1.5% difference for imprecision and 3% for total error/expanded uncertainty. CONCLUSION The EBV approach, using pRI, shows promise as a surrogate marker for biological variation and as a practical tool for determining performance limits in dogs and cats. Assuming accurate pRI generated on analyzers with stable analytical performance, this approach could offer benefits when expert recommendations or robust BV studies are lacking or yield conflicting results. Further research is needed to explore the applicability and advantages of the EBV in veterinary medicine.
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Affiliation(s)
- Simone Manzocchi
- IDEXX Laboratories Laboratory Analytical and Method Advisor (LAMA) Team, Milan, Italy
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4
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Anker SC, Morgenstern J, Adler J, Brune M, Brings S, Fleming T, Kliemank E, Zorn M, Fischer A, Szendroedi J, Kihm L, Zemva J. Verification of sex- and age-specific reference intervals for 13 serum steroids determined by mass spectrometry: evaluation of an indirect statistical approach. Clin Chem Lab Med 2023; 61:452-463. [PMID: 36537103 DOI: 10.1515/cclm-2022-0603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 11/16/2022] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Conventionally, reference intervals are established by direct methods, which require a well-characterized, obviously healthy study population. This elaborate approach is time consuming, costly and has rarely been applied to steroid hormones measured by mass spectrometry. In this feasibility study, we investigate whether indirect methods based on routine laboratory results can be used to verify reference intervals from external sources. METHODS A total of 11,259 serum samples were used to quantify 13 steroid hormones by mass spectrometry. For indirect estimation of reference intervals, we applied a "modified Hoffmann approach", and verified the results with a more sophisticated statistical method (refineR). We compared our results with those of four recent studies using direct approaches. RESULTS We evaluated a total of 81 sex- and age-specific reference intervals, for which at least 120 measurements were available. The overall agreement between indirectly and directly determined reference intervals was surprisingly good as nearly every fourth reference limit could be confirmed by narrow tolerance limits. Furthermore, lower reference limits could be provided for some low concentrated hormones by the indirect method. In cases of substantial deviations, our results matched the underlying data better than reference intervals from external studies. CONCLUSIONS Our study shows for the first time that indirect methods are a valuable tool to verify existing reference intervals for steroid hormones. A simple "modified Hoffmann approach" based on the general assumption of a normal or lognormal distribution model is sufficient for screening purposes, while the refineR algorithm may be used for a more detailed analysis.
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Affiliation(s)
- Sophie C Anker
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Jakob Morgenstern
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Jakob Adler
- Medical Laboratory for Clinical Chemistry, Microbiology, Infectious Diseases and Genetics Prof. Schenk/Dr. Ansorge & Colleagues, Magdeburg, Germany
| | - Maik Brune
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Sebastian Brings
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany.,Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Thomas Fleming
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Elisabeth Kliemank
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Markus Zorn
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Andreas Fischer
- Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany.,Division Vascular Signaling and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Julia Szendroedi
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Lars Kihm
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Johanna Zemva
- Department of Internal Medicine I and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
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5
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Haeckel R, Wosniok W, Streichert T. Review of potentials and limitations of indirect approaches for estimating reference limits/intervals of quantitative procedures in laboratory medicine. J LAB MED 2021. [DOI: 10.1515/labmed-2020-0131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Abstract
Reference intervals (RIs) can be determined by direct and indirect procedures. Both approaches identify a reference population from which the RIs are defined. The crucial difference between direct and indirect methods is that direct methods select particular individuals after individual anamnesis and medical examination have confirmed the absence of pathological conditions. These individuals form a reference subpopulation. Indirect methods select a reference subpopulation in which the individuals are not identified. They isolate a reference population from a mixed population of patients with pathological and non-pathological conditions by statistical reasoning.
At present, the direct procedure internationally recommended is the “gold standard”. It has, however, the disadvantage of high expenses which cannot easily be afforded by most medical laboratories. Therefore, laboratories adopt RIs established by direct methods from external sources requiring a high responsibility for transference problems which are usually neglected by most laboratories. These difficulties can be overcome by indirect procedures which can easily be performed by most laboratories without causing economic problems.
The present review focuses on indirect approaches. Various procedures are presented with their benefits and limitations. Preliminary simulation studies indicate that more recently developed concepts are superior to older approaches.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte , Bremen , Germany
| | - Werner Wosniok
- Institut für Statistik, Universität Bremen , Bremen , Germany
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6
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Arzideh F, Özcürümez M, Albers E, Haeckel R, Streichert T. Indirect estimation of reference intervals using first or last results and results from patients without repeated measurements. J LAB MED 2021. [DOI: 10.1515/labmed-2020-0149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Objectives
Indirect methods for the estimation of Reference Limits (RLs) use large data pools stored in modern laboratory information’s systems. To avoid correlation between observations repeated results from each patient should be excluded. Some data pools obtained are anonymized, and thereafter the data cannot be re-identified. The effect of the procedure of data selection on the estimations is not investigated yet.
Methods
We considered four parameters. Data sets were enclosed from two sources: a university hospital and a laboratory primarily reflecting a patient population from medical practitioners. Four algorithms were used for data selection, which generate first, last, all and non-repeated values. RLs were estimated through these data sets and compared.
Results
This study showed the broader reference range estimated by indirect methods if using the whole data set compared to first/last values or non-repeated values.
Conclusions
The use of all data without a filtering step results in a significant bias whereas the choice of first or last values has nearly no impact. The exclusion of repeated measurements results in narrower RLs. This influence confine the use of anonymous data sets where filtering is impossible for the estimation of RLs by indirect methods.
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Affiliation(s)
- Farhad Arzideh
- Institute for Clinical Chemistry, Faculty of Medicine , University of Cologne , Cologne , Germany
- Universitätsklinikum Knappschaftskrankenhaus Bochum GmbH , Bochum , Germany
| | - Mustafa Özcürümez
- Universitätsklinikum Knappschaftskrankenhaus Bochum GmbH , Bochum , Germany
| | - Eike Albers
- Institute for Clinical Chemistry, Faculty of Medicine , University of Cologne , Cologne , Germany
- MVZ Labor Dr. Quade & Kollegen GmbH , Cologne , Germany
| | - Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Klinikum Bremen Mitte , Bremen , Germany
| | - Thomas Streichert
- Institute for Clinical Chemistry, Faculty of Medicine , University of Cologne , Cologne , Germany
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Chen L, Zhang B, Yang L, Lou J, Jiang Y, Zhang S. Individualized Correction of the Interference of Hemolysis on Glycated Albumin Determined by the Ketamine Oxidase Method. Lab Med 2020; 51:151-156. [PMID: 31352488 DOI: 10.1093/labmed/lmz042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To investigate the effect of hemolysis on glycated albumin (GA) levels, as determined by the ketamine oxidase method. METHODS GA levels and the hemolysis index were determined in nonhemolyzed serum and hemolyzed serum from corresponding patients. We developed an equation to correct the interference of hemolysis on GA, using multiple regression analysis. RESULTS The degree of hemolysis was negatively correlated with GA levels (R2 = 0.9500). A correction equation for GA (corrected GA = 2.703 × OD of hemolysis + 1.044 × measured GA -0.906) can revert GA concentrations of hemolyzed specimens to values that were not significantly different from the GA concentration of corresponding nonhemolyzed specimens. The bias of GA concentrations before and after correction was statistically significantly different (P <.01). CONCLUSIONS Our results indicate that the level of GA measured through the ketamine oxidase method is negatively affected by hemolysis. The individualized correction of GA results provides increased accuracy in hemolyzed specimens.
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Affiliation(s)
- Li Chen
- Department of Obstetrics, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Bingfeng Zhang
- Department of Laboratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lu Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jianfang Lou
- Department of Laboratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ye Jiang
- Department of Laboratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Shichang Zhang
- Department of Obstetrics, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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8
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Pum JKW. Evaluating sample stability in the clinical laboratory with the help of linear and non-linear regression analysis. Clin Chem Lab Med 2020; 58:188-196. [PMID: 31702996 DOI: 10.1515/cclm-2019-0596] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/11/2019] [Indexed: 11/15/2022]
Abstract
As it is common practice for laboratories to store patient samples for a predefined period, allowing clinicians to request additional tests on previously collected samples, knowledge about sample stability is indispensable for the laboratorian. A common approach to estimating the maximum storage time is to use a discrete study design, measuring the analyte of interest at various time-points and then checking for significant differences with the help of a statistical test, such as Student's t-test, Wilcoxon's test or an analysis of variance (ANOVA) test. Because only discrete time intervals are considered, stability data can just be approximated. Alternatively, a continuous study design, as described by the Clinical and Laboratory Standards Institute (CLSI) for performing stability experiments for in vitro diagnostic reagents, can also be adopted by the clinical laboratory to evaluate the stability of biological samples. The major advantage of this approach is that it allows laboratories to define individual stability limits for different medical situations and offers more flexibility when choosing time-points for measurements. The intent of this paper is to demonstrate the evaluation of sample stability in the clinical laboratory with a continuous study design implemented with linear or non-linear regression analysis. Appropriate statistical modeling and acceptance criteria are presented, stability functions are described briefly, and checking the overall validity of the results is discussed.
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Affiliation(s)
- Joachim K W Pum
- Bioscientia Institut für Medizinische Diagnostik GmbH, MVZ Jena, Orlaweg 2, Jena 07743, Germany
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9
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A practical guide to validation and verification of analytical methods in the clinical laboratory. Adv Clin Chem 2019; 90:215-281. [PMID: 31122610 DOI: 10.1016/bs.acc.2019.01.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Although the measures to improve quality in the clinical laboratory have been enormous in the past years, not least of all due to the introduction of the ISO standards 15189 and 17025, the handling of validation and verification of method performance often still differs widely from laboratory to laboratory. Much of what is published on the topic contains complex statistics and is difficult to implement in routine laboratories. The result is, that this point is often neglected or implemented incorrectly, which in turn can lead to false conclusions about method performances, potentially compromising patient safety or contributing to incorrect diagnoses. As it has long become a standard requirement for accredited laboratories to evaluate and document the analytical performance of all methods not only prior to their first implementation, but also during ongoing operation, there is a need for clear, standardized and practical guidelines on the subject. This review summarizes the current literature on the topic, focusing on the requirements for method validations, or as the case may be, verifications and describes when to validate, when to verify and which statistical tests are appropriate for each. Proper interpretation of statistical test results and acceptance criteria for each procedure are alluded to. Specific topics, which are addressed, are precision and bias verification of quantitative, qualitative and semi-quantitative procedures, method comparisons with Bland-Altman Plots, Passing-Bablok regression analysis, 2×2 contingency tables and bubble charts, linearity studies, analytical sensitivity and specificity, performing carry-over studies and establishing and confirming reference ranges.
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10
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Oosterhuis WP, Bayat H, Armbruster D, Coskun A, Freeman KP, Kallner A, Koch D, Mackenzie F, Migliarino G, Orth M, Sandberg S, Sylte MS, Westgard S, Theodorsson E. The use of error and uncertainty methods in the medical laboratory. Clin Chem Lab Med 2019; 56:209-219. [PMID: 28796637 DOI: 10.1515/cclm-2017-0341] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/04/2017] [Indexed: 11/15/2022]
Abstract
Error methods - compared with uncertainty methods - offer simpler, more intuitive and practical procedures for calculating measurement uncertainty and conducting quality assurance in laboratory medicine. However, uncertainty methods are preferred in other fields of science as reflected by the guide to the expression of uncertainty in measurement. When laboratory results are used for supporting medical diagnoses, the total uncertainty consists only partially of analytical variation. Biological variation, pre- and postanalytical variation all need to be included. Furthermore, all components of the measuring procedure need to be taken into account. Performance specifications for diagnostic tests should include the diagnostic uncertainty of the entire testing process. Uncertainty methods may be particularly useful for this purpose but have yet to show their strength in laboratory medicine. The purpose of this paper is to elucidate the pros and cons of error and uncertainty methods as groundwork for future consensus on their use in practical performance specifications. Error and uncertainty methods are complementary when evaluating measurement data.
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Affiliation(s)
- Wytze P Oosterhuis
- Department of Clinical Chemistry and Haematology, Zuyderland Medical Center, Henri Dunantstraat 5, 6419 PC Heerlen, The Netherlands, Phone: +31 45 5766341
| | | | | | - Abdurrahman Coskun
- Acibadem University, School of Medicine, Department of Medical Biochemistry, Istanbul, Turkey
| | - Kathleen P Freeman
- IDEXX Laboratories, Ltd, Grange House, Sandbeck Industrial Estate, Wetherby, West Yorkshire, UK
| | - Anders Kallner
- Department of Clinical Chemistry, Karolinska University Hospital Stockholm, Stockholm, Sweden
| | - David Koch
- Emory University School of Medicine, Grady Memorial Hospital in Atlanta, GA, USA
| | - Finlay Mackenzie
- University Hospitals Birmingham NHS Foundation Trust, Institute of Research and Development, Birmingham, UK
| | | | - Matthias Orth
- Vinzenz von Paul Kliniken gGmbH, Institut für Laboratoriumsmedizin, Stuttgart, Baden-Wurttemberg, Germany
| | - Sverre Sandberg
- Norwegian Quality Improvement of Primary Care Laboratories (Noklus), Institute of Global Health and Primary Health Care, University of Bergen and Laboratory of Clinical Biochemistry Haukeland University Hospital, Bergen, Norway
| | - Marit S Sylte
- University of Bergen and Laboratory of Clinical Biochemistry Haukeland University Hospital, Bergen, Norway
| | | | - Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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11
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Measurement uncertainty in laboratory reports: A tool for improving the interpretation of test results. Clin Biochem 2018; 57:41-47. [DOI: 10.1016/j.clinbiochem.2018.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/12/2018] [Accepted: 03/12/2018] [Indexed: 11/20/2022]
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12
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Cosma C, Baggio S, Casarotti A, Zaninotto M, Faggian D, Plebani M. Immunofluorescence vs immunochemiluminescent methods: AIA 2000 vs Immulite 2000. Clin Biochem 2015; 48:1184-7. [PMID: 26049026 DOI: 10.1016/j.clinbiochem.2015.05.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/29/2015] [Accepted: 05/21/2015] [Indexed: 11/16/2022]
Abstract
The aim of this study was to evaluate the measurement of C-peptide, insulin, sex hormone binding globulin (SHBG), and dehydroepiandrosterone sulfate (DHEAS), tests of specific clinical value that are not frequently measured in routine clinical laboratories, carried out using an automated system, AIA 2000 (Tosoh). The obtained data demonstrated that the evaluated system, characterized by fluorescence system detector provides satisfactory analytical performance comparable to those of different instrument that use the well known and widely diffused chemiluminescent principle (Immulite 2000). These characteristics allow an excellent comparability between methods for the measurement of same specific hormones not frequently used in clinical practice.
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Affiliation(s)
- Chiara Cosma
- Department of Laboratory Medicine, University-Hospital, Padua, Italy.
| | - Silvia Baggio
- Department of Laboratory Medicine, University-Hospital, Padua, Italy
| | | | - Martina Zaninotto
- Department of Laboratory Medicine, University-Hospital, Padua, Italy
| | - Diego Faggian
- Department of Laboratory Medicine, University-Hospital, Padua, Italy
| | - Mario Plebani
- Department of Laboratory Medicine, University-Hospital, Padua, Italy
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13
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Park HI, Chae H, Kim M, Lee J, Kim Y. LEGO plot for simultaneous application of multiple quality requirements during trueness verification of quantitative laboratory tests. J Clin Lab Anal 2014; 28:147-56. [PMID: 24395762 DOI: 10.1002/jcla.21659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 06/24/2013] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND We developed a two-dimensional plot for viewing trueness that takes into account potential shift and variable quality requirements to verify trueness using certified reference material (CRM). METHODS Glucose, total cholesterol (TC), and creatinine levels were determined by two kinds of assay in two levels of a CRM. Available quality requirements were collected, codified, and sorted in an ascending order in the plot's header row. Centering on the mean of measured values from CRM, the "mean ± US CLIA '88 allowable total error" was located in the header of the leftmost and rightmost columns. Twenty points were created in intervening columns as potential shifts. Uncertainties were calculated according to regression between certified values and uncertainties of CRM, and positioned in the corresponding columns. Cells were assigned different colors where column and row intersected based on comparison of the 95% confidence interval of the percentage bias with each quality requirement. RESULTS A glucose assay failed to meet the highest quality criteria, for which shift of +0.13-0.14 mmol/l was required. A TC assay met the quality requirement and a shift of ±0.03 mmol/l was tolerable. A creatinine assay also met the quality requirement but any shift was not tolerable. CONCLUSION The plot provides a systematic view of the trueness of quantitative laboratory tests.
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Affiliation(s)
- Hae-il Park
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea; Catholic Laboratory Development and Evaluation Center, Clinical Research Coordinating Center, Catholic Medical Center, Seoul, Republic of Korea
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Abstract
Abstract
Clinical laboratories play an important role in improving patient care. The past decades have seen unbelievable, often unpredictable improvements in analytical performance. Although the seminal concept of the brain-to-brain laboratory loop has been described more than four decades ago, there is now a growing awareness about the importance of extra-analytical aspects in laboratory quality. According to this concept, all phases and activities of the testing cycle should be assessed, monitored and improved in order to decrease the total error rates thereby improving patients’ safety. Clinical Chemistry and Laboratory Medicine (CCLM) not only has followed the shift in perception of quality in the discipline, but has been the catalyst for promoting a large debate on this topic, underlining the value of papers dealing with errors in clinical laboratories and possible remedies, as well as new approaches to the definition of quality in pre-, intra-, and post-analytical steps. The celebration of the 50th anniversary of the CCLM journal offers the opportunity to recall and mention some milestones in the approach to quality and patient safety and to inform our readers, as well as laboratory professionals, clinicians and all the stakeholders of the willingness of the journal to maintain quality issues as central to its interest even in the future.
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Affiliation(s)
- Mario Plebani
- Department of Laboratory Medicine, University-Hospital of Padua, 35128 , Padua , Italy
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15
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Plebani M, Lippi G. Biological variation and reference change values: an essential piece of the puzzle of laboratory testing. Clin Chem Lab Med 2012; 50:189-90. [PMID: 22505541 DOI: 10.1515/cclm.2011.751] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lippi G, Sonntag O, Plebani M. Appropriate labelling of blood collection tubes: a step ahead towards patient's safety. Clin Chem Lab Med 2012; 49:1921-3. [PMID: 21958345 DOI: 10.1515/cclm.2011.736] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Haeckel R, Wosniok W, Al Shareef N. Permissible performance limits of regression analyses in method comparisons. Clin Chem Lab Med 2011; 49:1805-16. [PMID: 21815870 DOI: 10.1515/cclm.2011.668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Method comparisons are indispensable tools for the extensive validation of analytic procedures. Laboratories often only want to know whether an established procedure (x-method) can be replaced by another one (y-method) without interfering with diagnostic purposes. Then split patients' samples are analyzed more or less simultaneously with both procedures designed to measure the same quantity. The measured values are usually presented graphically as a scatter or difference plots. The two methods are considered to be equivalent (comparable) if the data pairs scatter around the line of equality (x=y line) within permissible equivalence lines. It is proposed to derive these limits of permissible imprecision limits which are based on false-positive error rates. If all data pairs are within the limits, both methods lead to comparable false error rates. If one or more data pairs are outside the permissible equivalence limits, the x-method cannot simply be replaced by the y-method and further studies are required. The discordance may be caused either by aberrant values (outliers), non-linearity, bias or a higher variation of e.g., the y-values. The spread around the line of best fit can detect possible interferences if more than 1% of the data pairs are outside permissible spread lines in a scatter plot. Because bias between methods and imprecision can be inter-related, both require specific examinations for their identification.
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Affiliation(s)
- Rainer Haeckel
- Bremer Zentrum für Laboratoriumsmedizin, Bremen, Germany.
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