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Biologic Variation Database, the 2014 Update

Celebrate 15 years of evidence-based quality goals! The 8th update of the biologic variation database, with updated specifications and new analytes for 2014.

Biological variation database, and quality specifications for imprecision, bias and total error (desirable and minimum). The 2014 update

Joana Minchinela[1,2], Carmen Ricós[1], Carmen Perich* [1,3], Pilar Fernández-Calle[1,4], Virtudes Alvarez[1,5], Mariví Domenech[1,6], Margarita Simón[1,7], Carmen Biosca[1,8], Beatriz Boned[1,9], Fernando Cava[1,10], José-Vicente García-Lario[1,11], Mª Pilar Fernández-Fernández[1]

1. Analytical Quality Commission, Spanish Society of Clinical Biochemistry and Molecular Pathology (SEQC)
2. Laboratori Clínic del Barcelonès Nord i Vallès Oriental Badalona)
3. Laboratori Clínic Bon Pastor (Barcelona)
4. Servicio Análisis Clínicos Hospital La Paz (Madrid)
5. Laboratori Clínic de l’Hospitalet (Barcelona)
6. Laboratori Clínic Manso (Barcelona)
7. Consorci del Laboratori Intercomarcal de l’Alt Penedès, l’Anoia i el Garraf (Barcelona)
8. Servei de Bioquímica Hospital GermansTrias i Pujol (Badalona)
9. Hospital Royo Villanova (Zaragoza)
10. Laboratorio Central BR Salud-Hospital Universitario Infanta Sofía (Madrid)
11. Laboratorio de Análisis Clínicos, Hospital Universitario Virgen de las Nieves (Granada).

* President of the Analytical Quality Committee, Spanish Society of Clinical Chemistry and Molecular Pathology (SEQC).

This is the 8th edition of data regarding the components of biological variation (intra and inter-individual -CVI and CVG , respectively) which compiles the published papers studying this item in healthy population, up to December 2013. The aim of this work is to provide quality specifications for imprecision, bias and total error to be used in laboratory medicine. The number of analytes with BV data available in this edition is: 357.

Here are the links to the updated tables:

In this edition 19 new analytes have been added (table 1); however the total number of analytes included here is shortly lower than the presented in previous edition, because components not directly measured but calculated from other analytes (i.e urine albumin/creatinine ratio, or serum LDL cholesterol calculated).

Some changes with respect to the 7th edition have been made; they are:

  • Serum and plasma Troponin-I: CVI values obtained in studies made within a 24 hours period are lower than those found in a longer time span. Because this analyte is mainly used in monitoring AMI at initial stage, with short-term monitoring, the specifications proposed have been derived from the 24-hour studies.
  • Urinary analytes have different CVI values, depending on the type of urine specimen. Quality specifications proposed are derived from the lowest specimen variability.
  • Some calculation errors, not detected in the previous edition have been amended here.
  • For analytes shown in table 2 new papers have been found, so quality specifications may have changed compared with those of the 7th edition.
  • Annex I, showing quality specifications, has a new column with the number of articlescompiled for each analyte. This information also appears in Annex II; however, the number of consultations received dealing with this item seemed us to indicate that many readers did not realize about annex II.
    This column highlights the robustness of CVI and CVG described (median of values compiled for each analyte). For example, there are 58 cholesterol CVI values coming from 46 papers, which results to a median of CVI=5.9% and a confidence interval (p<0.05) of 0.43, with values ranging from 2.4% to 9.7%. AST has 21 data coming from 13 papers, with a median of CVI = 12.3%, a confidence interval of 2.02% and values ranging between 4.7 and 24.2%. There are many analytes with a reduced number of papers published, thus the CVI and CVG estimated are quite poor and further studies should be made.

A brief summary: first edition was presented at the Stockholm international consensus conference on Strategies to Set Global Analytical Quality Specifications in Laboratory Medicine, was published in the Scan J Clin Lab Invest 1999;59:475-586 and also published on this website in June 2000. Successively, database has been updated every two years, up to the present 8th edition. Number of analytes included evolved from 316 up to the present 357. This information is also published at the SEQC website (http://www.seqc.es) in Spanish language.

 

Table 1. New analytes added to the 2014 edition
System Analyte           System Analyte          
Serum Carnitine, acyl free Plasma Parathyroid Hormone (PTH)
Plasma Cortisol Serum Plasmatic A Protein - Pregnancy associated (PAPP-A)
Serum C reactive-protein ultrasensitive Plasma Prolactin
Plasma D-Dimer (MoM) Serum Receptor for advanced glycated end-products (RAGE)
Plasma γ-Fibrinogen Plasma Testosterone
San- Hemoglobin A2 Plasma Thyrotropin (TSH)
Serum Hyaluronic acid Plasma Thyroxin, free (FT4)
Serum Inhibin B Plasma Triiodothyronine (T3)
Serum Kallicrein Plasma Troponin I
Serum LDL-Cholesterol, small dense
Table 2. Analytes with new papers added in this edition
System Analyte             System Analyte            
Serum α2-Macroglobulin Serum HDL Cholesterol
Serum Alanine aminotransferase (ALT) Serum LDL Cholesterol
Serum Albumin Blood Leukocytes, count
Serum Aspartate aminotransferase (AST) Serum Lutropin (LH)
Serum Bilirubin Blood Mean corpuscular hemoglobin (MCH)
Serum Calcium Blood Mean Corpuscular Hemoglobin Concentration (MCHC)
Serum Chloride Blood Mean Corpuscular Volume (MCV)
Serum Cholesterol Blood Platelet
Serum Creatinine Serum Potassium
Blood Erythrocytes, count Serum Protein
Serum Estradiol Serum Sex Hormone Binding Globulin (SHBG)
Serum Folitropin (FSH) Serum Sodium
Serum Alkaline phosphatase Serum Testosterone
Serum Phosphate Serum Triglyceride
Serum γ-Glutamyl transferase (GGT) Serum Troponin I
Serum Glucose Serum Urate
Blood Hematocrit Serum Urea
Blood Hemoglobin

 

-          Annex I, showing quality specifications, has a new column with the number of articles compiled for each analyte. This information also appears in Annex II; however, the number of consultations received dealing with this item seemed us to indicate that many readers did not realize about annex II.

This column highlights the robustness of CVI and CVG described (median of values compiled for each analyte). For example, there are 58 cholesterol CVI values coming from 46 papers, which results to a median of CVI=5.9% and a confidence interval (p<0.05) of 0.43, with values ranging from 2.4% to 9.7%.  AST has 21 data coming from de 13 papers, with a median of   CVI = 12.3%,   a confidence interval of 2.02% and values ranging between 4.7 and 24.2%. There are many analytes with a reduced number of papers published, thus the CVI and CVG estimated are quite poor and further studies should be made.