2019, Number 2
Measurement uncertainty in medical analysis laboratories
Full text
Language: Spanish
References: 13
Page: 68-73
PDF size: 217.11 Kb.
ABSTRACT
A brief historical review of the measurement uncertainty estimation models that have been proposed for the clinical laboratory in recent years as a way to satisfy requirement 5.5.1.4 ISO 15189.2012 is carried out. The compilation begins with the generic model GUM, in the «Bottom-Up» mode, adapted to the chemistry by EURACEHM, which when required to evaluate the uncertainty from its basic components, made it complex, difficult to apply to the routine of laboratories and without practical application. This is followed by simplified models of the «Top-Dowm» type, one proposed by the Royal College of Australasian Pathologists (RCPA) and then by the Spanish Society of Laboratory Medicine (SEQCML), which prioritize the contribution of intermediate precision in the medium term and add other contributions such as the uncertainty of the calibrator and eventually the one corresponding to the correction factor of the systematic error. The experimental application of this model demonstrates that expanded uncertainty remains virtually constant over the long term and does not reflect the behavior of analytical processes when evaluating data obtained from intercomparisons. These concepts are present in ISO Guide DTS 20914:2018 which is in a very preliminary stage of development. The uncertainty estimation mechanism proposed by Nordtest is then evaluated, which includes the intermediate precision data obtained from the internal quality control routine and the bias obtained from the results of the intercomparison tests, experimentally showing that with respect to the other models, it more realistically reflects the behavior of the long-term analysis procedures. The Workshop considers proposing the inclusion of the Nordtest model to the ISO DTS Guide 20914:2018, as an alternative calculation procedure.REFERENCES
Gella TF, Canalias RF, Izquierdo AS, Martínez VV, Sánchez MM. Recomendaciones para la estimación de la incertidumbre de medida en el laboratorio clínico Sociedad Española de Bioquímica Clínica y Patología Molecular. Disponible en: https://www.infobioquimica.com/radio/img/Recomendaciones%20para%20la%20estimaci%C3%B3n%20de%20la%20incertidumbre%20de%20medida%20en%20el%20laboratorio%20cl%C3%ADnico%20(2009).pdf visitado septiembre 2018.
Javier Gella. Trazabilidad e Incertidumbre de la Medición en el Laboratorio clínico. Universidad Autónoma de Barcelona y Comisión de Metrología de la Sociedad Española de Bioquímica Clínica y Patología Molecular. España. Disponible en: www.ifcc.org/media/216090/Trazabilidad%20e%20incertidumbre.pdf visitado septiembre 2018.
Magnusson B, Näykki T, Hovind H, Krysell M. Handbook for calculation of measurement uncertainty in environmental laboratories (NT TR 537-Edition 3.1). Available in: httpp://www.nordtest.info/index.php/technical-reports/item/handbook-for-calculation-of-measurement-uncertainty-in-environmental-laboratories-nt-tr-537-edition-3.html.