Pre-analytical variation of some haematological quantities.
BACKGROUND
It is customary to assume that pre-analytical variation is negligible if all pre-analytical sources of variation have been standardised. The aim of this study was to quantify the pre-analytical variation of some haematological quantities frequently measured in clinical laboratories.


METHODS
The experimental design considers different sources of pre-analytical variation that usually occur day-to-day for samples from patients.


RESULTS
The results demonstrate that for concentrations of erythrocytes, haemoglobin, leukocytes, neutrophilocytes (segmented) and lymphocytes, and for the volume fraction of erythrocytes ("packed cell volume") in blood, the pre-analytical variance is not negligible.


CONCLUSIONS
We suggest that these variances should be taken into account when estimating the uncertainty of measurement for patient results.
García-Panyella
Mariona
M
Laboratori Clínic, IDIBELL--Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Catalonia, Spain.
Padró-Miquel
Ariadna
A
Dot-Bach
Dolors
D
Fuentes-Arderiu
Xavier
X
D000704:Analysis of Variance; D016477:Artifacts; D006400:Hematocrit; D006403:Hematologic Tests / Q000379:methods; D006801:Humans; D035501:Uncertainty