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

2002 ◽  
Vol 39 (6) ◽  
pp. 543-550 ◽  
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.

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

2015 ◽  
Vol 53 (2) ◽  
Author(s):  
Carmen Perich ◽  
Joana Minchinela ◽  
Carmen Ricós ◽  
Pilar Fernández-Calle ◽  
Virtudes Alvarez ◽  
...  
Keyword(s):  
Numerical Data ◽  
Relevant Information ◽  
Laboratory Medicine ◽  
Biological Variation ◽  
The Internet ◽  
Analytical Quality ◽  
Database Structure ◽  
Variation Database ◽  
Quality Specifications ◽  
Allowable Error

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.

scholarly journals 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

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.

Pre-analytical quality indicators in laboratory medicine: Performance of laboratories participating in the IFCC working group “Laboratory Errors and Patient Safety” project

2019 ◽  
Vol 497 ◽  
pp. 35-40 ◽  
Author(s):  
Laura Sciacovelli ◽  
Giuseppe Lippi ◽  
Zorica Sumarac ◽  
Isabel Garcia del Pino Castro ◽  
Agnes Ivanov ◽  
...  
Keyword(s):  
Patient Safety ◽  
Quality Indicators ◽  
Working Group ◽  
Laboratory Medicine ◽  
Analytical Quality ◽  
Laboratory Errors

Sample collections from healthy volunteers for biological variation estimates’ update: a new project undertaken by the Working Group on Biological Variation established by the European Federation of Clinical Chemistry and Laboratory Medicine

2016 ◽  
Vol 54 (10) ◽  
Author(s):  
Anna Carobene ◽  
Marta Strollo ◽  
Niels Jonker ◽  
Gerhard Barla ◽  
William A. Bartlett ◽  
...  
Keyword(s):  
Working Group ◽  
Clinical Chemistry ◽  
Laboratory Medicine ◽  
Biological Variation ◽  
European Federation ◽  
Laboratory Measurements ◽  
Controlled Conditions ◽  
Edta Plasma ◽  
Blood Specimens

AbstractBackground:Biological variation (BV) data have many fundamental applications in laboratory medicine. At the 1st Strategic Conference of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) the reliability and limitations of current BV data were discussed. The EFLM Working Group on Biological Variation is working to increase the quality of BV data by developing a European project to establish a biobank of samples from healthy subjects to be used to produce high quality BV data.Methods:The project involved six European laboratories (Milan, Italy; Bergen, Norway; Madrid, Spain; Padua, Italy; Istanbul, Turkey; Assen, The Netherlands). Blood samples were collected from 97 volunteers (44 men, aged 20–60 years; 43 women, aged 20–50 years; 10 women, aged 55–69 years). Initial subject inclusion required that participants completed an enrolment questionnaire to verify their health status. The volunteers provided blood specimens once per week for 10 weeks. A short questionnaire was completed and some laboratory tests were performed at each sampling consisting of blood collected under controlled conditions to provide serum, KResults:Samples from six out of the 97 enroled subjects were discarded as a consequence of abnormal laboratory measurements. A biobank of 18,000 aliquots was established consisting of 120 aliquots of serum, 40 of EDTA-plasma, and 40 of citrated-plasma from each subject. The samples were stored at –80 °C.Conclusions:A biobank of well-characterised samples collected under controlled conditions has been established delivering a European resource to enable production of contemporary BV data.

Supplements to a recent proposal for permissible uncertainty of measurements in laboratory medicine

2016 ◽  
Vol 40 (2) ◽  
Author(s):  
Rainer Haeckel ◽  
Werner Wosniok ◽  
Eberhard Gurr ◽  
Burkhard Peil
Keyword(s):  
Working Group ◽  
Laboratory Medicine ◽  
Reference Intervals ◽  
Standard Uncertainty ◽  
Biological Variation ◽  
Recent Proposal ◽  
New Approach ◽  
Permissible Limits ◽  
Uncertainty Of Measurements ◽  
Variation Data

Abstract:The DGKL Working Group Guide Limits (Arbeitsgruppe Richtwerte) has published a proposal for deriving permissible analytical uncertainty limits related to biological variation data. Reference intervals were used to estimate biological variation. Biological variation data as basis for permissible uncertainty limits are generally accepted. These concepts usually apply a fixed factor leading to unrealistic stringent limits for quantities with a relatively small biological variation and to very permissive limits for quantities with relatively large biological variation. The working group has suggested a non-linear relation between biological variation and permissible uncertainty limits. The new approach has been exemplified with 84 quantities listed in the RiliBÄK (official German guidelines). The algorithms published allowed to derive permissible limits for all quantitative measurands in laboratory medicine. After its publication, three supplements appear necessary: 1. additional specifications of standard uncertainty, 2. a discussion on permissible limits for diagnosis and monitoring purposes, and 3. a discussion on circular reasoning in our approach.

Analytical quality specifications for common reference intervals

2004 ◽  
Vol 42 (7) ◽  
Author(s):  
Carmen Ricós ◽  
Maria Vicenta Doménech ◽  
Carmen Perich
Keyword(s):  
Real Life ◽  
Reference Interval ◽  
Population Based ◽  
Reference Intervals ◽  
Healthy Population ◽  
Analytical Quality ◽  
Related Factors ◽  
Cross Sectional ◽  
Reference Change Value ◽  
Quality Specifications

AbstractInterpretation oflaboratory test results requires comparison to some type of reference value or reference interval. These comparisons can be cross-sectional (population-based reference interval and cut-off values) or longitudinal (reference change value). Quality specifications for cross-sectional comparison have been established by determining the influence of analytical bias and imprecision on the percentage ofthe healthy population falling outside the reference limits, when sharing population-based reference intervals in a Gaussian distribution ofresults. Quality specifications for longitudinal comparisons are equally important and are often overlooked, since less work has been done in this area. Some criteria suggest that a difference between consecutive results designates a true change in a patient health status when the difference is higher than the within-subject biological variation plus the within-laboratory analytical variation. In this chapter we discuss the clinical considerations and laboratory-related factors that must be considered when quality specifications are applied to sharing reference comparisons. Real life experience shows that different analytical methods can produce comparable results when common quality goals are established, and quality can be achieved through a willingness to work together. Within the existing organization, the current specifications for analytical quality and a dedication to quality health care makes it possible to achieve transferability between laboratories within a geographic area.

The 1999 Stockholm Consensus Conference on quality specifications in laboratory medicine

2015 ◽  
Vol 53 (6) ◽  
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.

An assessment of clinical laboratory performance for the determination of manganese in blood and urine

2016 ◽  
Vol 54 (12) ◽  
Author(s):  
Meredith L. Praamsma ◽  
Josiane Arnaud ◽  
David Bisson ◽  
Stuart Kerr ◽  
Chris F. Harrington ◽  
...  
Keyword(s):  
Characteristic Function ◽  
Clinical Laboratory ◽  
External Quality Assessment ◽  
Biological Variation ◽  
External Quality ◽  
Laboratory Performance ◽  
Quality Specifications ◽  
The Relationship ◽  
Mn Concentration

AbstractBackground:Proficiency testing or external quality assessment schemes (PT/EQASs) are an important method of assessing laboratory performance. As each scheme establishes assigned values and acceptable ranges for the analyte according to its own criteria, monitoring of participant performance varies according to the scheme and can lead to conflicting conclusions.Methods:Standard deviations (SDs) for PT were derived from Thompson’s and biological variation models applied to blood and urine manganese (Mn) robust data from four EQASs from North America and Europe. The fitness for purpose was verified by applying these SDs to individual results.Results:Using Thompson characteristic function the relationship between SD and Mn concentration, expressed in nmol/L was the square root of [19.7Conclusions:The biological variation model can be used to propose quality specifications for blood, however it could not be applied to urine. The Thompson characteristic function model could be applied to derive quality specifications for Mn in urine and, to a lesser extent in blood. The more lenient quality specifications for blood highlight the difficulty of determining Mn in this matrix. Further work is needed to harmonize PT, such as using assigned ranges for the specimens.

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