Cautions in the Adoption of Common Reference Intervals

Transferability of test results for a given analyte has long been a goal of the laboratory community. Achievement of transferability will require develop-ment of standardized methods that have the least pos-siblemeasurement uncertainty and are traceable to ref-erence standards. Once accomplished, transferability will allow comparison of laboratory results regardless of the individual performing laboratory and will pro-vide long-term stability of results, enabling longitudi-nal results to be followed for individual patients. Transferability remains an elusive goal, however. Ana-lytical hindrances include the lack of established refer-encemeasurement systems formany quantities, lack of traceability of field methods to the reference system, and lot-to-lot variability in reagents and calibrators