2001 Update

Analytical Quality Commission of the Spanish Society of Clinical Chemistry and Molecular Pathology (SEQC).

On June 2000 a compilation of data on within- and between-subject biological variation, as well as the consequent specifications for analytical imprecision, bias and total error (inaccuracy), was published on this website. At that time we expressed our wish to maintain this information updated, and this is the first revision. The majority of changes are minor as compared with the previous; however, they are listed here in alphabetical order:

• CA 125: a new work including four groups of subjects that increases both CVw and CVg.
• Cholesterol: one article had an erratum, which resulted in an increase of CVw when corrected
• Deoxypiridoline/creatinine: a new work that increases the CVg
• Dehydroepiandrosteron sulphate, one article had an erratum, which resulted in an high increase of CVw when corrected, because only two works are compiled
• Galactosyl hydroxylisine: the first article published in 2001.
• HDL-cholesterol: a mistake in the previous print has been amended Hemoglobin A1C: the first article published in 2001.
• Homocysteine: a new work that increases both CVw and CVg.
• Immunoglobulin A: one article had an erratum, which resulted in an increase of CVw when corrected.
• Interleukin1-b: the first article published in 2001.
• Interleukin-8: the first article published in 2001.
• N-acetyl-glucosaminidase: a mistake in the previous compilation (various urine types were mixed-up) has been amended.
• pH hydrogen ion was originally expressed as concentration. We have calculated the CVw in pH units by transforming data from reference 68 to pH units (SDanalytical goal = 0.08, mean 7.420) using the following formula: CVw = 100*2SDanalytical goal/mean
• Plasminogen: a mistake in the previous compilation has been amended (data from a single day were included).
• Procollagen type I - C-terminal: a mistake in the previous work has been amended (still no data for CVg available)
• Reticulocyte: the first article published in 2001.
• Testosterone: lower CVw values in this new work because data from men and women have been combined here.
• Saliva testosterone: a typo in the previous work has been amended
• Tissue polypeptide specific antigen: a typo in the previous compilation has been amended
• Tumor Necrosis Factor-a: the first article published in 2001
• Vanilmandelic acid: forgotten in the previous work

Annex I. Table of biological variation
Annex II. Bibliographic references
Annex III. Articles