Biological variation database: structure and criteria used for generation and update

AbstractNumerical data on the components of biological variation (BV) have many uses in laboratory medicine, including in the setting of analytical quality specifications, generation of reference change values and assessment of the utility of conventional reference values.Generation of a series of up-to-date comprehensive database of components of BV was initiated in 1997, integrating the more relevant information found in publications concerning BV. A scoring system was designed to evaluate the robustness of the data included. The database has been updated every 2 years, made available on the Internet and derived analytical quality specifications for imprecision, bias and total allowable error included in the tabulation of data.Our aim here is to document, in detail, the methodology we used to evaluate the reliability of the included data compiled from the published literature. To date, our approach has not been explicitly documented, although the principles have been presented at many symposia, courses and conferences.

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Combination of Analytical Quality Specifications Based on Biological Within- and Between-Subject Variation

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456320203900601 ◽

2002 ◽

Vol 39 (6) ◽

pp. 543-550 ◽

Cited By ~ 25

Author(s):

Per Hyltoft Petersen ◽

Callum G Fraser ◽

Lone Jørgensen ◽

Ivan Brandslund ◽

Marta Stahl ◽

...

Keyword(s):

Coefficient Of Variation ◽

Working Group ◽

Population Based ◽

Laboratory Medicine ◽

Biological Variation ◽

Analytical Quality ◽

External Quality ◽

Analytical Imprecision ◽

Quality Specifications ◽

Group Concept

At a conference on ‘Strategies to Set Global Analytical Quality Specifications in Laboratory Medicine’ in Stockholm 1999, a hierarchy of models to set analytical quality specifications was decided. The consensus agreement from the conference defined the highest level as ‘evaluation of the effect of analytical performance on clinical outcomes in specific clinical settings’ and the second level as ‘data based on components of biological variation’. Here, the many proposals for analytical quality specifications based on biological variation are examined and the outcomes of the different models for maximum allowable combined analytical imprecision and bias are illustrated graphically. The following models were investigated. (1) The Cotlove et al. (1970) model defining analytical imprecision (%CVA) in relation to the within-subject biological variation (%CVw-s) as: %CVA≤ 0·5 × %CVW-S (where %CV is percentage coefficient of variation), (2) The Gowans et al. (1988) concept, which defines a functional relationship between analytical imprecision and bias for the maximum allowable combination of errors for the purpose of sharing common reference intervals. (3) The European Group for the Evaluation of Reagents and Analytical Systems in Laboratory Medicine (EGE Lab) Working Group concept, which combines the Cotlove model with the Gowans concept using the maximal acceptable bias. (4) The External Quality Assessment (EQA) Organizers Working Group concept, which is close to the EGE Lab Working Group concept, but follows the Gowans et al. concept of imprecision up to the limit defined by the model of Cotlove et al. (5) The ‘three-level’ concept classifying analytical quality into three levels: optimum, desirable and minimum. The figures created clearly demonstrated that the results obtained were determined by the basic assumptions made. When %CVW-S is small compared with the population-based coefficient of variation [%CVp = (%CV2W-S +%CV2B-S)1/2], the EGE Lab and EQA Organizers Working Group concepts become similar. Examples of analytical quality specifications based on biological variations are listed and an application on external quality control is illustrated for plasma creatinine.

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The 1999 Stockholm Consensus Conference on quality specifications in laboratory medicine

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2014-0914 ◽

2015 ◽

Vol 53 (6) ◽

Cited By ~ 14

Author(s):

Callum G. Fraser

Keyword(s):

Laboratory Medicine ◽

Consensus Conference ◽

Analytical Performance ◽

Performance Goals ◽

Analytical Quality ◽

Global Consensus ◽

Current State ◽

Regulatory Bodies ◽

Quality Specifications ◽

Stockholm Conference

AbstractThe setting of analytical quality specifications in laboratory medicine has been a topic of discussion and debate for over 50 years: 15 years ago, as the subject matured and a profusion of recommendations appeared, many of them from expert groups, it was realised by a number of leading professionals that there was a need for a global consensus on the setting of such specifications. The Stockholm Conference held in 1999 on “Strategies to set global analytical quality specifications in laboratory medicine” achieved this and advocated the ubiquitous application of a hierarchical structure of approaches. The hierarchy has five levels, namely: 1) evaluation of the effect of analytical performance on clinical outcomes in specific clinical settings; 2) evaluation of the effect of analytical performance on clinical decisions in general using a) data based on components of biological variation, or b) analysis of clinicians’ opinions; 3) published professional recommendations from a) national and international expert bodies, or b) expert local groups or individuals; 4) performance goals set by a) regulatory bodies, or b) organisers of external quality assessment (EQA) schemes; and 5) goals based on the current state of the art as a) demonstrated by data from EQA or proficiency testing scheme, or b) found in current publications on methodology. This approach has been much used since its wide promulgation, but there have been ongoing criticisms and new developments. The time seems right for an objective reappraisal of recommended strategies to set analytical performance goals.

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Pediatric Within-Day Biological Variation and Quality Specifications for 38 Biochemical Markers in the CALIPER Cohort

Clinical Chemistry ◽

10.1373/clinchem.2013.214312 ◽

2014 ◽

Vol 60 (3) ◽

pp. 518-529 ◽

Cited By ~ 21

Author(s):

Dana Bailey ◽

Victoria Bevilacqua ◽

David A Colantonio ◽

Maria D Pasic ◽

Nandita Perumal ◽

...

Keyword(s):

Pediatric Population ◽

Biological Variation ◽

Interindividual Variation ◽

Healthy Children ◽

Analytical Quality ◽

Reference Change Value ◽

Variation Characteristics ◽

Quality Specifications ◽

Study Participants ◽

Insight Into

Abstract BACKGROUND Studies of biological variation provide insight into the physiological changes that occur within and between study participants. Values obtained from such investigations are important for patient monitoring and for establishing quality specifications. In this study we evaluated the short-term biological variation of 38 chemistry, lipid, enzyme, and protein analytes in a pediatric population, assessed the effect of age partitions on interindividual variation, and compared the findings to adult values. METHODS Four plasma samples each were obtained within 8 h from 29 healthy children (45% males), age 4–18 years. Samples were stored at −80 °C and analyzed in 3 batches, with samples from 9–10 study participants per batch. Within-person and between-person biological variation values were established using nested ANOVA after exclusion of outliers by use of the Tukey outlier test. Analytical quality specifications were established with the Fraser method. RESULTS Biological variation coefficients and analytical goals were established for 38 analytes. Age partitioning was required for 6 analytes. Biological variation characteristics of 14 assays (37%) were distinct from adult values found in the Westgard database on biological variation. Biological variation characteristics were established for 2 previously unreported analytes, unconjugated bilirubin and soluble transferrin receptor. CONCLUSIONS This study is the first to examine biological variation and to establish analytical quality specifications on the basis of biological variation for common assays in a pediatric population. These results provide insight into pediatric physiology, are of use for reference change value calculations, clarify the appropriateness of reference interval use, and aid in the development of quality management strategies specific to pediatric laboratories.

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Strategies to set global analytical quality specifications in laboratory medicine: 10 years on from the Stockholm consensus conference

Accreditation and Quality Assurance ◽

10.1007/s00769-009-0630-8 ◽

2010 ◽

Vol 15 (6) ◽

pp. 323-330 ◽

Cited By ~ 16

Author(s):

Per Hyltoft Petersen ◽

Callum G. Fraser

Keyword(s):

Laboratory Medicine ◽

Consensus Conference ◽

Analytical Quality ◽

Quality Specifications

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OPERATIVE-SEARCH MONITORING THE INTERNET AS AN ELEMENT OF COUNTERING CRIMES OF EXTREMIST DIRECTION

Bulletin of the Kostroma state University ◽

10.34216/1998-0817-2020-26-2-235-241 ◽

2020 ◽

pp. 235-241

Author(s):

Aleksey V. Kutuzov

Keyword(s):

Law Enforcement ◽

Relevant Information ◽

Theoretical Development ◽

The Internet ◽

Legal Basis ◽

Main Attention ◽

Legal Norms ◽

A Priority ◽

Use Of Internet ◽

Source Of Information

The article substantiates the need to use Internet monitoring as a priority source of information in countering extremism. Various approaches to understanding the defi nition of the category of «operational search», «law enforcement» monitoring of the Internet are analysed, the theoretical development of the implementation of this category in the science of operational search is investigated. The goals and subjects of law enforcement monitoring are identifi ed. The main attention is paid to the legal basis for the use of Internet monitoring in the detection and investigation of extremist crimes. In the course of the study hermeneutic, formal-logical, logical-legal and comparative-legal methods were employed, which were used both individually and collectively in the analysis of legal norms, achievements of science and practice, and development of proposals to refi ne the conduct of operational-search measures on the Internet when solving extremist crimes. The author’s defi nition of «operational-search monitoring» of the Internet is provided. Proposals have been made to improve the activities of police units when conducting monitoring of the Internet in the context of the search for relevant information to the disclosure and investigation of crimes of that category.

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A voyage to Ancient Greek Harbours on board Limenoscope

Water Science & Technology Water Supply ◽

10.2166/ws.2007.029 ◽

2007 ◽

Vol 7 (1) ◽

pp. 253-260 ◽

Cited By ~ 1

Author(s):

T. Theodoulou ◽

C. Memos

Keyword(s):

Black Sea ◽

General Public ◽

Aegean Sea ◽

Relevant Information ◽

The Black Sea ◽

Ancient Greek ◽

Web Based ◽

Database Structure ◽

Historical Role ◽

Concise Information

Limenoscope is a web based database aiming at promoting the cultural heritage regarding ancient Greek harbours and disseminate the relevant information equally to the general public and to researchers with an interest in that particular cognitive field. The scope of the project is the realization of a database, where one can search for concise information relevant to the historical role, the topography, the morphology, as well as the technical works and installations of ancient harbours in the Mediterranean and the Black Sea. The Database started off with the registration of harbours located in the Aegean Sea and Cyprus, dating from Archaic to Byzantine times. Special emphasis is laid on the bibliographical update of the data forms of the harbour sites, as well as on the related references in ancient literature. The database enables the locating of these sites on a general map, where photographs, plans etc. are also archived. The principles of the database structure are briefly presented along with an example, that of the harbour of Phalasarna, among the harbours registered therein.

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Spanish society of laboratory medicine external quality assurance programmes: evolution of the analytical performance of clinical laboratories over 30 years and comparison with other programmes

Advances in Laboratory Medicine / Avances en Medicina de Laboratorio ◽

10.1515/almed-2020-0019 ◽

2020 ◽

Vol 1 (2) ◽

Author(s):

Carmen Perich ◽

Carmen Ricós ◽

Fernando Marqués ◽

Joana Minchinela ◽

Angel Salas ◽

...

Keyword(s):

Quality Assurance ◽

State Of The Art ◽

Laboratory Medicine ◽

Analytical Performance ◽

External Quality Assurance ◽

Biological Variability ◽

External Quality ◽

Spanish Society ◽

Clinical Laboratories ◽

Quality Specifications

AbstractThe purpose of this study is to understand the evolution of the analytical performance of the laboratories participating in the Spanish society of laboratory medicine (SEQCML) external quality assurance (EQA) programmes during its 30 years of operation and to compare it with the performance of other EQA programmes to establish whether the results are similar. The results obtained during this period are evaluated by applying the biological variability (BV) and state of the art-derived quality specifications. In addition, the results are compared with those obtained by other EQA programme organisations. It is noted that the laboratories participating in the EQA–SEQCML programmes have improved their performance over 30 years of experience and that the specifications derived from biological variation are achievable. It is difficult to compare EQA programmes, due to lack of accessibility and the differences in the design of these programmes (control materials, calculations used and analytical specifications established). The data from this study show that for some biological magnitudes the results obtained by the programmes are not yet harmonised, although efforts are being made to achieve this. Organisers of EQA programmes should also join the harmonisation effort by providing information on their results to enable comparison.

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Biological variation of cardiac myosin-binding protein C in healthy individuals

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2021-0306 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Bashir Alaour ◽

Torbjørn Omland ◽

Janniche Torsvik ◽

Thomas E. Kaier ◽

Marit S. Sylte ◽

...

Keyword(s):

Risk Stratification ◽

Protein C ◽

Myocardial Injury ◽

Binding Protein ◽

Biological Variation ◽

Cardiac Myosin ◽

Analytical Quality ◽

Myosin Binding Protein ◽

Myosin Binding Protein C ◽

Myosin Binding

Abstract Objectives Cardiac myosin-binding protein C (cMyC) is a novel biomarker of myocardial injury, with a promising role in the triage and risk stratification of patients presenting with acute cardiac disease. In this study, we assess the weekly biological variation of cMyC, to examine its potential in monitoring chronic myocardial injury, and to suggest analytical quality specification for routine use of the test in clinical practice. Methods Thirty healthy volunteers were included. Non-fasting samples were obtained once a week for ten consecutive weeks. Samples were tested in duplicate on the Erenna® platform by EMD Millipore Corporation. Outlying measurements and subjects were identified and excluded systematically, and homogeneity of analytical and within-subject variances was achieved before calculating the biological variability (CVI and CVG), reference change values (RCV) and index of individuality (II). Results Mean age was 38 (range, 21–64) years, and 16 participants were women (53%). The biological variation, RCV and II with 95% confidence interval (CI) were: CVA (%) 19.5 (17.8–21.6), CVI (%) 17.8 (14.8–21.0), CVG (%) 66.9 (50.4–109.9), RCV (%) 106.7 (96.6–120.1)/−51.6 (−54.6 to −49.1) and II 0.42 (0.29–0.56). There was a trend for women to have lower CVG. The calculated RCVs were comparable between genders. Conclusions cMyC exhibits acceptable RCV and low II suggesting that it could be suitable for disease monitoring, risk stratification and prognostication if measured serially. Analytical quality specifications based on biological variation are similar to those for cardiac troponin and should be achievable at clinically relevant concentrations.

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