Table.

Prerequisites for use of common reference intervals.

Category of Prerequisite	Prerequisite	Responsibility
Analytical	Existence of a Reference Measurement	IFCC, JCTLM, National and International Metrology
	System (accuracy base)	Institutes
	Existence of traceable field methods	Manufacturers
	Correct implementation of the methods in the clinical laboratories	Clinical laboratories
	Control of the performances of the field methods to keep them within stated limits for imprecision and bias	Clinical laboratories, EQAS organisers
Clinical	Accurate definition of reference intervals providing information on the influence of biological and environmental factors	Joint effort–IFCC, manufacturers and clinical laboratories
	Compatible pre-analytical phase	Clinical laboratories
	Validation of the applicability of the common reference intervals to the laboratory’s own population	Clinical laboratories
	Adoption of the common reference intervals	Clinical laboratories

IFCC, International Federation of Clinical Chemistry and Laboratory Medicine

JCTLM, Joint Committee for Traceability in Laboratory Medicine

EQAS, External Quality Assessment Scheme