Quality control

The ability of CNRL members to perform the basic tasks is evaluated by periodic, external inter-laboratory quality control assessments (click here for 2000 QCA, click here for 2002 QCA and comparison). EISS does not implement an accreditation system, but CNRL members have agreed that at least a 90% correct score for the basic tasks should be obtained. When applying this criterion to CNRL laboratories that participated in the QCAs of 2000 and 2002 (N=14), the proportion of laboratories with a correct score of ≥90% was similar for detection, but increased considerably for characterisation (See table below). Most notable was the increase in 100% correct score for detection, subtyping and characterisation (See table below). Laboratories that scored less than 90% in a certain task are offered assistance by the QCA Task Group and other CNRL members in the form of training, protocols and materials.

Comparison of correct result scores of the same 14 laboratories in the 2000 and 2002 QCAs ^a for detection of influenza A and B virus and respiratory syncytial virus (RSV), subtyping of influenza A virus, strain characterisation of influenza virus and typing of RSV

Type of analysis	Correct score	Number of laboratories in year (total correct/total performing)
		2000	2002
Detection influenza A and B virus and RSV	≥90%	10/14 (71%)	11/14 (79%)
	100%	4/14 (29%)	10/14 (71%)
Subtyping influenza A virus	≥90%	11/13 (85%)	n.a. b
	100%	5/13 (38%)	12/14 (86%)
Strain characterisation influenza virus	≥90%	3/5 (60%)	10/10 (100%)
	100%	3/5 (60%)	9/10 (90%)
Typing RSV c	100%	5/5 (100%)	7/7 (100%)

^a QCA 2000 and 2002
^b n.a. = not applicable, as the number of specimens (7) was too low to distinguish between ≥90% and 100% correct score.
^c A correct score of ≥90% was not used as the number of specimens containing RSV was too low to distinguish between ≥90% and 100% correct score.