Reliability of biological variation data available in an online database: need for improvement

2015 ◽  
Vol 53 (6) ◽  
Author(s):  
Anna Carobene
Keyword(s):  
Clinical Chemistry ◽  
Glycated Albumin ◽  
Biological Variation ◽  
European Federation ◽  
Reactive Protein ◽  
Hemoglobin C ◽  
Number Of Factors ◽  
Quality Specifications ◽  
Glutamyl Transferase ◽  
Serial Measurements

AbstractBiological variation (BV) data enable assessment of the significance of changes in serial measurements observed within a subject and are used to set analytical quality specifications. This data is available in a database held in Westgard website (The BV data currently hosted on the Westgard website was examined. Distribution of measurands stratified by the number of cited references upon which the database entry is based and the distribution of papers stratified by publication year, are shown. Moreover, BV data available in literature for glycated hemoglobin, C-reactive protein, glycated albumin, alanine aminotransferase, aspartate aminotransferase and γ-glutamyl transferase are evaluated.The results obtained show that most BV data come just from a few papers or only one paper and that a lot of publications are dated, therefore this data is too obsolete to be used. Furthermore critical review of the BV database highlights a number of factors that might impact on the reliability of the BV data entries and translation into current practice.A number of issues clearly undermine the value of the current database. These issues are being considered by the European Federation of Clinical Chemistry and Laboratory Medicine, biological variation working group, in collaboration with a Spanish group responsible for the database updating.

scholarly journals An overview of EFLM harmonization activities in Europe

2018 ◽  
Vol 56 (10) ◽  
pp. 1591-1597 ◽  
Author(s):  
Eric S. Kilpatrick ◽  
Sverre Sandberg
Keyword(s):  
Best Practice ◽  
Clinical Chemistry ◽  
Laboratory Medicine ◽  
Biological Variation ◽  
European Federation ◽  
Eu Countries ◽  
European Guidelines ◽  
Common Basis ◽  
Evaluation Procedures ◽  
E Learning

Abstract The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has initiated many harmonization activities in all phases of the examination process. The EFLM is dealing with both the scientific and the educational aspects of harmonization, with the intention of disseminating best practice in laboratory medicine throughout Europe. Priorities have been given (1) to establish a standard for conducting and assessing biological variation studies and to construct an evidence based EFLM webpage on biological variation data, (2) to harmonize preanalytical procedures by producing European guidelines, (3) to improve test ordering and interpretation, (4) to produce other common European guidelines for laboratory medicine and play an active part in development of clinical guidelines, (5) to establish a common basis for communicating laboratory results to patients, (6) to harmonize units of measurement throughout Europe, (7) to harmonize preanalytical procedures in molecular diagnostics and (8) to harmonize and optimize test evaluation procedures. The EFLM is also now launching the 5th version of the European Syllabus to help the education of European Specialists in Laboratory Medicine (EuSpLM), which is being supported by the development of e-learning courses. A register of EuSpLM is already established for members of National Societies in EU countries, and a similar register will be established for specialists in non-EU countries.

scholarly journals The EuBIVAS Project: Within- and Between-Subject Biological Variation Data for Serum Creatinine Using Enzymatic and Alkaline Picrate Methods and Implications for Monitoring

2017 ◽  
Vol 63 (9) ◽  
pp. 1527-1536 ◽  
Author(s):  
Anna Carobene ◽  
Irene Marino ◽  
Abdurrahman Coşkun ◽  
Mustafa Serteser ◽  
Ibrahim Unsal ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Clinical Chemistry ◽  
Biological Variation ◽  
European Federation ◽  
Healthy Individuals ◽  
Homogeneity Analysis ◽  
Variation Data ◽  
Performance Specifications ◽  
Age Range ◽  
Analytical Variation

Abstract BACKGROUND The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined biological variation (BV) indices. EuBIVAS determined BV for serum creatinine using the enzymatic and alkaline picrate measurement methods. METHOD In total, 91 healthy individuals (38 males, 53 females; age range, 21–69 years) were bled for 10 consecutive weeks at 6 European laboratories. An equivalent protocol was followed at each center. Sera were stored at −80 °C before analysis. Analyses for each patient were performed in duplicate within a single run on an ADVIA 2400 system (San Raffaele Hospital, Milan). The data were subjected to outlier and homogeneity analysis before performing CV-ANOVA to determine BV and analytical variation (CVA) estimates with confidence intervals (CI). RESULTS The within-subject BV estimates [CVI (95% CI)] were similar for enzymatic [4.4% (4.2–4.7)] and alkaline picrate [4.7% (4.4–4.9)] methods and lower than the estimate presently available online (CVI = 5.9%). No significant male/female BV differences were found. Significant differences were observed in mean creatinine values between men and women and between Turkish individuals and those of other nationalities. Between-subject BV (CVG) estimates, stratified accordingly, produced CVG values similar to historical BV data. CVA was 1.1% for the enzymatic and 4.4% for alkaline picrate methods, indicating that alkaline picrate methods fail to fulfill analytical performance specifications for imprecision (CVAPS). CONCLUSIONS The serum creatinine CVI obtained by EuBIVAS specifies a more stringent CVAPS than previously identified. The alkaline picrate method failed to meet this CVAPS, raising questions regarding its future use.

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.

Long-term biological variation estimates of 13 hematological parameters in healthy Chinese subjects

2020 ◽  
Vol 58 (8) ◽  
pp. 1282-1290 ◽  
Author(s):  
Chenbin Li ◽  
Mingting Peng ◽  
Ji Wu ◽  
Zhongli Du ◽  
Hong Lu ◽  
...  
Keyword(s):  
Complete Blood Count ◽  
Clinical Chemistry ◽  
Hematological Parameters ◽  
Age Distribution ◽  
Turnover Time ◽  
Biological Variation ◽  
European Federation ◽  
Mean Values ◽  
Healthy Chinese ◽  
Chinese Subjects

AbstractBackgroundThe complete blood count (CBC) is a basic test routinely ordered by physicians as a part of initial diagnostic work-up on their patients. To ensure safe clinical application of the CBC, reliable biological variation (BV) data are needed to establish analytical performance specifications. Our aim was to define the BV of CBC parameters using a rigorous protocol that is compliant with the Biological Variation Data Critical Appraisal Checklist (BIVAC) provided by the European Federation of Clinical Chemistry and Laboratory Medicine.MethodsBlood samples drawn from 41 healthy Chinese subjects (22 females and 19 males; 23–59 years of age) once monthly for 6 consecutive months were analyzed using an ABX Pentra 80 instrument. The instrument was precisely calibrated. All samples were analyzed in duplicate for 13 CBC parameters. The data were assessed for outliers, normality, and variance homogeneity prior to nested ANOVA. Gender-stratified within-subject (CVI) and between-subject (CVG) BV estimates were calculated.ResultsThe number of remaining data for each subject was 442–484 after removing outliers. No significant differences existed between female/male CVI estimates. Except for leukocytes, neutrophils, and lymphocytes, the mean values of 10 parameters differed significantly between genders, rendering partitioning of CVG data between genders. No significant differences were detected between most BV estimates and recently published estimates representing a Europid population.ConclusionsMost BV estimates in BIVAC-compliant studies are similar. The turnover time of blood cells and age distribution of participants should be considered in a CBC BV study. Our study will contribute to global BV estimates and future studies.

Age dependence of within-subject biological variation of nine common clinical chemistry analytes

2012 ◽  
Vol 50 (5) ◽  
Author(s):  
Anna Carobene ◽  
Maria Stella Graziani ◽  
Claudia Lo Cascio ◽  
Livia Tretti ◽  
Eveline Cremonese ◽  
...  
Keyword(s):  
Clinical Chemistry ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
The Elderly ◽  
Time Of Day ◽  
Biological Variation ◽  
Age Dependence ◽  
Within Subjects ◽  
Quality Specifications ◽  
Age Range

AbstractThe knowledge of biological variation (BV) data is important for clinical decisions and as a basis for defining analytical quality specifications. However, in gene\xadrating reliable data of biological variation there are still some unsolved problems, such as age dependence. The aim of our work is to verify this aspect.Twenty-six subjects divided into three groups by age were studied. Blood samples were collected in lithium heparin tubes for four weeks at one week intervals, on the same day of the week (Tuesday) and at the same time of day (8–9 a.m.) by the same phlebotomist. They were analysed in duplicate for creatinine, urate, calcium, albumin, total cholesterol, high density lipoprotein (HDL) and low density lipoprotein (LDL)-cholesterol, triglycerides and iron. After outlier exclusion by Cochran\u2019s test, components of biological variation were calculated by ANOVA. The significance of the differences between results of the classes was also calculated with the Student\u2019s test (t-test) and the Fisher\u2019s test (F-test).Excluding albumin, the group 3 results (age range from 78 to 98 years) showed significantly lower CV within subjects (CVOur data seem to highlight the relevance of the age when choosing the reference subjects for biological variation studies. The level of within-subject biological variation of the elderly group may have been further reduced by the homogeneity of the group constituted by individuals living together in the same nursing home.

scholarly journals The EuBIVAS: Within- and Between-Subject Biological Variation Data for Electrolytes, Lipids, Urea, Uric Acid, Total Protein, Total Bilirubin, Direct Bilirubin, and Glucose

2018 ◽  
Vol 64 (9) ◽  
pp. 1380-1393 ◽  
Author(s):  
Aasne K Aarsand ◽  
Jorge Díaz-Garzón ◽  
Pilar Fernandez-Calle ◽  
Elena Guerra ◽  
Massimo Locatelli ◽  
...  
Keyword(s):  
Uric Acid ◽  
Total Protein ◽  
Total Bilirubin ◽  
Service Providers ◽  
Clinical Chemistry ◽  
Hdl Cholesterol ◽  
Biological Variation ◽  
Direct Bilirubin ◽  
European Federation ◽  
Variation Data

Abstract BACKGROUND The European Federation of Clinical Chemistry and Laboratory Medicine European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined data describing biological variation (BV) of clinically important measurands. Here, EuBIVAS-based BV estimates of serum electrolytes, lipids, urea, uric acid, total protein, total bilirubin, direct bilirubin, and glucose, as well as their associated analytical performance specifications (APSs), are presented. METHOD Samples were drawn from 91 healthy individuals (38 male, 53 female; age range, 21–69 years) for 10 consecutive weeks at 6 European laboratories. Samples were stored at −80 °C before duplicate analysis of all samples on an ADVIA 2400 (Siemens Healthineers). Outlier and homogeneity analyses were performed, followed by CV-ANOVA on trend-corrected data, when relevant, to determine BV estimates with CIs. RESULTS The within-subject BV (CVI) estimates of all measurands, except for urea and LDL cholesterol, were lower than estimates available in an online BV database, with differences being most pronounced for HDL cholesterol, glucose, and direct bilirubin. Significant differences in CVI for men and women/women <50 years of age were evident for uric acid, triglycerides, and urea. The CVA obtained for sodium and magnesium exceeded the EuBIVAS-based APS for imprecision. CONCLUSIONS The EuBIVAS, which is fully compliant with the recently published Biological Variation Data Critical Appraisal Checklist, has produced well-characterized, high-quality BV estimates utilizing a stringent experimental protocol. These new reference data deliver revised and more exacting APS and reference change values for commonly used clinically important measurands, thus having direct relevance to diagnostics manufacturers, service providers, clinical users, and ultimately patients.

scholarly journals Determining Plasma Protein Variation Parameters as a Prerequisite for Biomarker Studies—A TMT-Based LC-MSMS Proteome Investigation

Proteomes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 47
Author(s):  
Lou-Ann C. Andersen ◽  
Nicolai Bjødstrup Palstrøm ◽  
Axel Diederichsen ◽  
Jes Sanddal Lindholt ◽  
Lars Melholt Rasmussen ◽  
...  
Keyword(s):  
Sample Size ◽  
Plasma Protein ◽  
Plasma Proteins ◽  
Clinical Chemistry ◽  
Biological Variation ◽  
Sample Size Determination ◽  
Clinical Proteomics ◽  
European Federation ◽  
Plasma Samples ◽  
Proteomic Approach

Specific plasma proteins serve as valuable markers for various diseases and are in many cases routinely measured in clinical laboratories by fully automated systems. For safe diagnostics and monitoring using these markers, it is important to ensure an analytical quality in line with clinical needs. For this purpose, information on the analytical and the biological variation of the measured plasma protein, also in the context of the discovery and validation of novel, disease protein biomarkers, is important, particularly in relation to for sample size calculations in clinical studies. Nevertheless, information on the biological variation of the majority of medium-to-high abundant plasma proteins is largely absent. In this study, we hypothesized that it is possible to generate data on inter-individual biological variation in combination with analytical variation of several hundred abundant plasma proteins, by applying LC-MS/MS in combination with relative quantification using isobaric tagging (10-plex TMT-labeling) to plasma samples. Using this analytical proteomic approach, we analyzed 42 plasma samples prepared in doublets, and estimated the technical, inter-individual biological, and total variation of 265 of the most abundant proteins present in human plasma thereby creating the prerequisites for power analysis and sample size determination in future clinical proteomics studies. Our results demonstrated that only five samples per group may provide sufficient statistical power for most of the analyzed proteins if relative changes in abundances >1.5-fold are expected. Seventeen of the measured proteins are present in the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Biological Variation Database, and demonstrated remarkably similar biological CV’s to the corresponding CV’s listed in the EFLM database suggesting that the generated proteomic determined variation knowledge is useful for large-scale determination of plasma protein variations.

scholarly journals The Biological Variation Data Critical Appraisal Checklist: A Standard for Evaluating Studies on Biological Variation

2018 ◽  
Vol 64 (3) ◽  
pp. 501-514 ◽  
Author(s):  
Aasne K Aarsand ◽  
Thomas Røraas ◽  
Pilar Fernandez-Calle ◽  
Carmen Ricos ◽  
Jorge Díaz-Garzón ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Critical Appraisal ◽  
Clinical Chemistry ◽  
Essential Elements ◽  
Biological Variation ◽  
European Federation ◽  
Variation Data ◽  
Global Estimates ◽  
Variance Homogeneity

Abstract BACKGROUND Concern has been raised about the quality of available biological variation (BV) estimates and the effect of their application in clinical practice. A European Federation of Clinical Chemistry and Laboratory Medicine Task and Finish Group has addressed this issue. The aim of this report is to (a) describe the Biological Variation Data Critical Appraisal Checklist (BIVAC), which verifies whether publications have included all essential elements that may impact the veracity of associated BV estimates, (b) use the BIVAC to critically appraise existing BV publications on enzymes, lipids, kidney, and diabetes-related measurands, and (c) apply metaanalysis to deliver a global within-subject BV (CVI) estimate for alanine aminotransferase (ALT). METHODS In the BIVAC, publications were rated as A, B, C, or D, indicating descending compliance for 14 BIVAC quality items, focusing on study design, methodology, and statistical handling. A D grade indicated that associated BV estimates should not be applied in clinical practice. Systematic searches were applied to identify BV studies for 28 different measurands. RESULTS In total, 128 publications were identified, providing 935 different BV estimates. Nine percent achieved D scores. Outlier analysis and variance homogeneity testing were scored as C in >60% of 847 cases. Metaanalysis delivered a CVI estimate for ALT of 15.4%. CONCLUSIONS Application of BIVAC to BV publications identified deficiencies in required study detail and delivery, especially for statistical analysis. Those deficiencies impact the veracity of BV estimates. BV data from BIVAC-compliant studies can be combined to deliver robust global estimates for safe clinical application.

scholarly journals Analytical Performance Specifications for Lipoprotein(a), Apolipoprotein B-100, and Apolipoprotein A-I Using the Biological Variation Model in the EuBIVAS Population

2020 ◽  
Vol 66 (5) ◽  
pp. 727-736 ◽  
Author(s):  
Noemie Clouet-Foraison ◽  
Santica M Marcovina ◽  
Elena Guerra ◽  
Aasne K Aarsand ◽  
Abdurrahman Coşkun ◽  
...  
Keyword(s):  
Apolipoprotein B ◽  
Clinical Chemistry ◽  
Biological Variation ◽  
Analytical Performance ◽  
European Federation ◽  
Published Data ◽  
Cvd Risk ◽  
Lipoprotein A ◽  
Apolipoprotein A ◽  
Performance Specifications

Abstract Background With increased interest in lipoprotein(a) (Lp[a]) concentration as a target for risk reduction and growing clinical evidence of its impact on cardiovascular disease (CVD) risk, rigorous analytical performance specifications (APS) and accuracy targets for Lp(a) are required. We investigated the biological variation (BV) of Lp(a), and 2 other major biomarkers of CVD, apolipoprotein A-I (apoA-I) and apolipoprotein B-100 (apoB), in the European Biological Variation Study population. Method Serum samples were drawn from 91 healthy individuals for 10 consecutive weeks at 6 European laboratories and analyzed in duplicate on a Roche Cobas 8000 c702. Outlier, homogeneity, and trend analysis were performed, followed by CV-ANOVA to determine BV estimates and their 95% CIs. These estimates were used to calculate APS and reference change values. For Lp(a), BV estimates were determined on normalized concentration quintiles. Results Within-subject BV estimates were significantly different between sexes for Lp(a) and between women aged <50 and >50 years for apoA-I and apoB. Lp(a) APS was constant across concentration quintiles and, overall, lower than APS based on currently published data, whereas results were similar for apoA-I and apoB. Conclusion Using a fully Biological Variation Data Critical Appraisal Checklist (BIVAC)–compliant protocol, our study data confirm BV estimates of Lp(a) listed in the European Federation of Clinical Chemistry and Laboratory Medicine database and reinforce concerns expressed in recent articles regarding the suitability of older APS recommendations for Lp(a) measurements. Given the heterogeneity of Lp(a), more BIVAC-compliant studies on large numbers of individuals of different ethnic groups would be desirable.

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