Approaches for providing target values to improve usefulness of external quality assessment scheme. The Spanish experience.

The aim of this communication is to highlight the specific aspects of external quality assessment schemes that need to be discussed in a European context: target values, transferability of results and accredit of laboratories. The Spanish situation is presented here. The most reliable way to provide target values is to analyse the control samples by reference methods. However, it is not possible for the majority of national schemes and other approaches are presently used: the verification of consensus means is a practicable solution adopted in Spain. An initial network involving selected routine laboratories has been developed, to attain transferability of results. The traceability of routine calibrators from certified reference materials should be demonstrated. To accredit laboratories for licensing is a complex activity that should consider many aspects, results from the national quality assessment scheme bring one. A scoring system is being used in Spain for guidance, and the complete guidelines are under preparation.