Standardization and harmonization in laboratory medicine: not only for clinical chemistry measurands

Both terms standardization and harmonization are often used interchangeably, because their final endpoint is basically identical, i.e., providing laboratory results to stakeholders (i.e., clinicians and patients) that could be compared across different laboratories, over time. Nonetheless, these two terms reflect in their essence to different concepts. Standardization should be used when test results are uniform across routine measurement procedures and traceable to a recognized standard reference material defined by the International System of Units (SI) through a high-order primary reference material and/or a reference measurement procedure. Harmonization, is instead aimed to make test results more comparable irrespective of the analytical procedure, mainly because neither a reference measurement procedure (RPM) or a primary reference material (RM) are available. Notably, this latter case involves the vast majority of the analytes measured in clinical laboratories, most of which represent an essential source of information for both clinical decision-making and patient care. It is hence increasingly clear that efforts should not only be made for developing further standardization initiatives, but also to assure comparability of laboratory results and information for those measurands for which no RMP neither RM were, are and will be available in the near future. In addition, standardization and harmonization initiatives should be promoted not only in the analytical phase, but throughout all other steps of the total testing process (TTP), thus improving quality and safety of laboratory information.