Table 24. Multi-analyser comparability: possible materials to be used.

Recommended practice	Reanalysis of fresh patient samples on the different systems at a frequency defined by the laboratory and statistical validation according to standard ISO 5725-6:1994 (24).
Acceptable practice	IQC within acceptable limits for all systems EQA tested on all analysers with laboratory interpretation by the laboratory (statistical evaluation based on ISO 5725-6:1994) or by the EQA providers (provided that the frequency of these EQAs is sufficient)
Unacceptable practice	Different acceptable limits on analysers. Compare only by looking at the average of normal patients (unable to quickly detect a discrepancy in one of the systems).
IQC – internal quality control. EQA – external quality assessment.