Table 13. New batch of IQC.

Recommended practice	Overlap period for each IQC batch change. If possible, several days (depending on how long the batch has been used): 2 days in haematology, 10 days if the batch is used over a long period of time). Consultation of peer averages if available (external IQC).
Acceptable practice	Minimum overlap period of one day and use of previous CVs (may nevertheless deviate significantly from the objective).
Unacceptable practice	No evaluation of a new batch of practice IQC before use with risk of impact on the patient in case of simultaneous deterioration of the reagent and the IQC.
IQC – internal quality control.