Data Bank, Part I: Analytes A-L
Data Bank, Part II: Analytes L-Z
References

This data bank, originally published as Sebastián-Gámbaro MA, Lirón-Hernández FJ, Fuentes-Arderiu X, Intra- and inter-individual biological variability data bank, Eur J Clin Chem Biochem 1997;35:845-852 is posted by kind permission of the publisher, Walter de Gruyter, and the authors.

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Different results are usually observed when a quantity is measured in different specimens from the same individual obtained over a time span. For an individual, this variation is due to both imprecision of the measurement procedure, the metrological variability, and the rhythmic and random fluctuations of the quantity value around a virtual homeostatic set point, the intra-individual biological variability.

On the other hand, when studying the intra-individual biological variation of a quantity a mean value, the virtual homestatic set point, is estimated for each individual participating in the study. The variation among these means is due to the inter-individual biological variability.

Many valuable uses of data on intra- and inter-individual variability have been proposed in clinical laboratory sciences (1-6), including, among others, the evaluation of the significance of changes in serial results, and the establishment of several metrologic requirements, specially those related to:

• day-to-day imprecision,
• systematic error,
• error of measurement,
• interference and carry-over,
• lack of linearity.

Because this kind of data can not be produced by each laboratory, it is important that such a information be updated and published periodically. This report is a compilation of data from 1951 to 1996, including 107 publications on biological variability in healthy individuals (7-113), and updates previous compilations prepared by J.W. Ross and C.G. Fraser (114-116). Most of the citations are in Medline database (National Library of Medicine, National Institutes of Health, Bethesda, USA), others are in Italian and Spanish "peer-reviewed" journals not included in Medline. Data on biological variability in diseased individuals have not been included in this compilation.

Table 1 shows, for each quantity, the median of the coefficients of variation published describing the inter- and intra-individual biological variation, the shortest and the longest time span among those studied, and the references of these studies.

For all the uses of biological variation data mentioned above, the availability of a single value -perhaps two values if significant sex difference exist- of coefficient of variation corresponding to healthy people, instead of a long collection of values that may create indecision and confusion, has practical interest for most of the potential and real users of biological variability data. If a single value is retained for routine use, the median is the most appropriate because this value is not influenced by possible outliers or extreme values.

Table Description. Medians of the coefficients of inter-individual (med CV_Bb) and intra-individual (med CV_Bw) biological variation of biological quantities in healthy subjects estimated in different studies with different time spans. [The symbols used in this table are: h = hour; d = day; wk = week; mo = month; a = year; r = mass concentration; b = catalytic concentration ; m = mass; c = substance concentration; n/N = entitic amount of substance; n = amount of substance; r = partial pressure; arb = arbitrary; t = time; C = number concentration; f = volume fraction; V/N = entitic volume; f = volume; x = substance fraction; l = length; z = catalitic activity; NO = no data available]. According to ISO, IUPAC and IFCC recommendations the comma is used as decimal sign.

Quantity	time span range	med CVBw	med CVBb	References
Serum-a- Acid glycoprotein; r	21 d-20 wk	11,3	20,1	7, 8, 9
Serum-Acid phosphatase; b	0,5 h-15 wk	7,3	8,0	10, 11
Serum-Acid phosphatase, bone type; b	4 wk	10,8	13,3	12
Serum-Adenosine deaminase; b	1 a	11,7	NO	13
Serum-Alanine aminopeptidase; b	8 wk	1,4	NO	14
Serum-Alanine aminotransferase; b	6 h-1 a	23,0	41,1	10, 11, 13, 15, 16, 17, 18, 19, 20
Serum-Albumin; r	6 h-1 a	2,8	4,4	8, 10, 11, 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29
Urine(daily)-Albumin; m	6 wk	70,0	55,0	30
Urine(daily)-Albumin; r	6 wk	61,0	53,0	30
Urine(morning)-Albumin; r	2-6 wk	35,5	36,0	30, 31
Urine(random)-Albumin; r	6 wk	86,0	61,0	30
Plasma-Aldosterone; c	7 d	29,4	40,1	32
Serum-Alkaline phosphatase; b	6 h- 1 a	5,9	22,3	10, 11, 12, 13, 15, 17, 18, 19, 24, 26, 28, 33, 34, 35, 36, 37
Serum-Alkaline phosphatase, bone type; b	1 mo	6,6	35,6	12
Serum-Alkaline phosphatase,placental type; b	6 mo	11,9	52,9	38
Urine(daily)-Ammonium; n	4 wk	24,7	NO	39
Serum-a-Amylase; b	24 h-1 a	8,7	25,8	12, 15, 16, 19, 20, 40

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Quantity	time span range	med CVBw	med CVBb	References
Serum-Dehydroepiandrosterone sulfate; c	1 wk	3,4	30,0	32
Serum-11-Deoxycortisol; c	1 wk	21,3	31,5	32
Urine(random)-Deoxypyridinoline;c Urine(random)-Creatininium;c	4 wk	10,8	13,0	34
Blood-Erythrocytes; C	1 mo-20 wk	2,1	7,0	19, 82
Blood-Erythrocytes; f	1 mo	2,4	NO	19, 82, 83
Blood-Erythrocytes; V/N	20 wk	1,1	4,1	82
Serum-Estradiol-17b; c	7 d-6 mo	21,7	88,7	32, 84
Serum-Ferritin; r	24 h-24 wk	12,8	13,5	15, 19, 33, 83
Serum-Ferroxidase; r	5 d- 5 mo	5,6	11,2	7, 33
Serum-Follitropin; c arb	1 d-1 a	17,3	33,6	32, 84, 85, 86
Serum-Fructosamine; c	5 d- 5 wk	3,7	7,6	87, 88
Serum-a1-Globulin; r	1 mo-1 a	10,0	22,6	13, 19, 29
Serum-a2-Globulin; r	1 mo-1 a	10,2	12,7	13, 19, 29
Serum-b-Globulin; r	1 mo-1 a	9,6	9,2	13, 19, 29
Serum-g-Globulin; r	1 mo-1 a	11,2	12,3	13, 19, 29
Serum-Glucose; c	24 h- 1 a	6,1	7,8	13, 15, 16, 19, 24, 25, 37, 56, 66, 87, 89
Serum-g-Glutamyltransferase; b	24 h- 1 a	12,2	41,0	13, 15, 16, 17, 19, 20, 37
Serum-Glutathione; c	8 mo	9,1	20	81
Serum-Glycated albumin; r	5 d	5,2	10,3	87
Serum-Glycated protein; r	5 d	0,9	11,9	87
(Blood)Hb-Glycohemoglobin; x	11 wk	8,8	NO	66
Blood-Granulocytes; C	20 wk	18,3	28,0	82
Leukocytes-Granulocytes; d	20 wk	7,2	14,6	82

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