Point of view regarding traceability and measurement uncertainty in medical laboratory accreditation

International standard ISO 15189 is a tool embodying basic qualities and scientific grounds based on test results, published in 2003. The Japan Accreditation Board for Conformity Assessment (JAB) and the Japanese Committee for Clinical Laboratory Standards (JCCLS) jointly developed the accreditation scheme for medical laboratories based on the accreditation criteria of ISO 15189, and the JAB started its accreditation service in August 2005. The service is now in its fourth year. As of the end of fiscal 2008, the total number of accredited medical laboratories was 46, consisting of nine belonging to university hospitals, nine to other medical institutes, and twenty-eight commercial laboratories. ISO 15189, which ensures the quality and competence of medical laboratories, is an excellent standard, and it is hoped that it will lead to the generation of high quality medical testing data using effective management systems. Each medical laboratory requires a program for the calibration of measurement systems and examination results by tracing to SI units or referring to a natural constant or other stated reference, and an estimate of measurement uncertainty when relevant and possible. For measurements whose uncertainty cannot be estimated, all aspects of uncertainty affecting the measurements are taken into account in "fishbone diagrams". These are important for medical doctors to understand the results and decide on courses of treatment or observation. For this, medical laboratories need to ensure traceability and assess measurement uncertainty. Finally, the goal of an accredited medical laboratory is to continue "offering effective laboratory services for patient medicine and treatment, supporting the health of the nation".