2009, Number 1
Metrological traceability, analytical validation and interlaboratory consensus on clinical laboratory accuracy
Terrés SAM
Full text
Language: Spanish
References: 16
Page: 27-35
PDF size: 172.26 Kb.
ABSTRACT
Background: Metrology is the science of measurement. It includes all aspects, both theoretical and practical with reference to measurements, whatever their uncertainty, and in whatever fields of science or technology they occur, including Laboratory Medicine. Within metrology, traceability stands on a central point. It is the property of a measurand outcome or from the value of a calibrator in order to be relate with specific references which are usually international or national standards through a non-interrupted chain of comparisons with established uncertainty. Goal: ISO 15189:2003 was developed in order to establish requisites for Clinical Laboratories Accreditation through Quality Management and Technical Competence from pre through post examination stages. From the metrological perspective the most important issue is located on the analytical phase, where the main goal is to provide reliable results, requiring that laboratory professionals understand clearly the importance of traceability, uncertainty, validation, consensus in order to establish the shared responsibility of Manufacturers of Medical Devices and Analytical systems, Clinical Laboratories responsibility on validation and internal quality control plus the role of Proficiency Testing Programs on laboratories consensus accuracy. Material and methods: This is a brief review through specific questions of ISO 17511:2003 In Vitro Diagnostic Medical Devices–Measurement of Quantities in Biological Samples– Metrological Traceability of Values Assigned to Calibrators and Control Materials where a process evaluation, definitions, and practical cases are presented in order to allow applicability on internal quality control programs and on external proficiency testing schemes. Outcome: Clinical laboratory test’s accuracy depends mainly on metrological traceability, which depends on analytical sensitivity and specificity of developed system by manufacturers. Certified Primary Reference Materials (PRM) use is restricted to research and development laboratories because of high costs and limited availability, in consequence, clinical laboratories and proficiency testing schemes depend mainly on commercial materials. Traceability is a manufacturer’s responsibility who shall document it clearly in order to be provided to final users in order allow them validate and control internally through systematic quality control. Proficiency Testing Programs have a complementary role on achieving accuracy utilizing homogeneous quality control material which should be similar to that used on internal quality control programs. Conclusion: Accuracy and applicability of laboratory tests are two interdependent elements that must be understood in order to be achieved effectively. This is a shared responsibility where all the system’s components must collaborate symmetrically including providers, laboratories and accreditation agencies.REFERENCES