Chapter 17 - Harmonization of results among laboratories

Abstract

Harmonization is achieving equivalent results, within clinically meaningful limits, among different measurement procedures for the same laboratory test. Standardization means equivalent results are achieved by having calibration of measurement procedures traceable to a reference measurement procedure (RMP) or certified reference material (CRM). The International Organization for Standardization (ISO) has published standards for metrological traceability of results for patient samples through an unbroken chain of calibrations to CRMs and RMPs. The Joint Committee for Traceability in Laboratory Medicine lists CRMs, RMPs, and calibration laboratories that conform to the ISO requirements. Commutability of matrix-based CRMs with patient samples is an essential property for their successful use in a calibration hierarchy. ISO has published a new standard for applying a harmonization protocol to achieve metrological traceability when there is no suitable CRM or RMP. Laboratories can verify calibration traceability by comparing patient sample results with a RMP, using a commutable matrix-based CRM or participating in an external quality assessment program that uses commutable samples.