Minimum analytical quality specifications of inter-laboratory comparisons: agreement among Spanish EQAP organizers.

BACKGROUND: Four Spanish scientific societies organizing external quality assessment programs (EQAP) formed a working group to promote the use of common minimum quality specifications for clinical tests. Laboratories that do not meet the minimum specifications are encouraged to make immediate review of the analytical procedure affected and to implement corrective actions if necessary. METHODS: The philosophy was to use the 95th percentile of results sent to EQAP (expressed in terms of percentage deviation from the target value) obtained for all results (except the outliers) during a cycle of 1 year. The target value for a number of analytes of the basic biochemistry program was established as the overall mean. However, because of the substantial discrepancies between routine methods for basic hematology, hormones, proteins, therapeutic drugs and tumor markers, the target in these cases was the peer group mean. RESULTS: The resulting specifications were quite similar to those established in the US (CLIA), and Germany (Richtlinie). CONCLUSIONS: The proposed specifications stand for the minimum level of quality to be attained for laboratories, to assure harmonized service performance. They have nothing to do with satisfying clinical requirements, which are the final level of quality to be reached, and that is strongly recommended in our organizations by means of documents, courses, symposiums and all types of educational activities.

State-of-the-art Approach to Goal Setting.

Four external quality assurance programs combined their data to calculate the minimum acceptable quality specifications for laboratory testing. Other sources of quality specifications may be too stringent for the current market, or too lenient given the clinical demands on the test result, but these state-of-the-art goals may be practical and useful. Two main approaches were used: (1) defining the 95% percentile and comparing with other quality specifications, and (2) using an iterative approach to increase the quality specification until 90% of laboratories could achieve 75% of their results within the specification. 72 out of 82 analytes followed procedure 2.

Respuesta de los autores «Ventajas del control de calidad interno de gestión externa» / Reply for author «Advantages of externally managed internal quality control»

No disponible

Control interno de la calidad vs control externo de la calidad / Internal quality control vs external quality control

El control interno de la calidad es el procedimiento que monitoriza la calidad de los resultados y permite aceptar o rechazar las series analíticas. Existen 2 variedades, el modelo de gestión interna, donde el tratamiento estadístico de los resultados control se realiza únicamente con los datos obtenidos por el propio laboratorio, y el control interno con gestión externa, donde el procesamiento estadístico se realiza con los datos obtenidos por el propio laboratorio y por otros laboratorios. Ambos sirven para calcular la imprecisión analítica y no son adecuados para evaluar el error total ni el sesgo. El control externo de la calidad es la determinación del desempeño de cada laboratorio mediante la comparación con otros laboratorios. Existen 3 modelos, los 2 primeros: evaluación externa de la calidad y ensayo de aptitud son muy similares, y se centran en las prestaciones analíticas, mientras que el tercero, denominado garantía externa de la calidad, tiene en cuenta todas las fases del laboratorio. Con el control externo de la calidad, en cualquiera de sus modelos, se mide el error total de cada mensurando, porque la muestra de control, que es ciega para el participante, se analiza una única vez. A largo plazo, cuando se dispone de todos los resultados del programa, se puede medir el error sistemático o sesgo. A la luz de los requisitos legales vigentes, las buenas prácticas del laboratorio y los artículos de referencia internacionales, el control interno de la calidad no es ni sustituye al control de la calidad externo (AU)

Internal quality control is the procedure used for monitoring the analytical process and to accept or reject the analytical run. There are two models: internal quality control that exclusively uses the control results from the own laboratory, and internal control externally managed, that also uses control data from other laboratories reported to an external organization. Both of them measure the analytical imprecision but are not adequate to estimate neither bias nor inaccuracy (total error). External quality control evaluates the laboratory performance by comparing with other laboratories, through an external organization. There are three models, external quality assessment and proficiency testing which are almost the same and are focused on the analytical process and external quality assurance that applies to all laboratory processes. The three models of external control measure total error, because the control sample (blind for the laboratory) is tested in singleton. At long-term, when all results for one cycle are available, laboratory bias may also been calculated. From the light of legal requirements, good laboraotry practices and papers from widely accepted authors, internal quality control is not and do not substitute external quality control (AU)

Grado de implantación de especificaciones de la calidad analítica en España / Level of implementation of analytical quality specifications in Spain

Objetivos: Este trabajo pretende conocer el grado de implantación de las especificaciones de la calidad en los laboratorios clínicos de España y concretamente de las especificaciones mínimas de la calidad analítica consensuadas por el Comité de Expertos Interdisciplinar sobre Especificaciones de la Calidad (CEIEC) en el Laboratorio Clínico, así como la opinión del sector respecto a la necesidad del establecimiento de valores preceptivos de requisitos de la calidad analítica: Material y método: Se diseñó una encuesta que constaba de 22 preguntas, 4 de ellas de tipo descriptivo, 16 retrospectivas y 2 prospectivas. El periodo de recogida de respuestas fue de septiembre a noviembre de 2012. Como requisito de los encuestados solo se consideró que participasen en algún programa de intercomparación de las sociedades científicas españolas representadas en el citado comité. El número de encuestas remitidas fue de 1.738. Resultados: Se recibieron 340 respuestas (19,6% del total). El 59% de los que respondieron tiene implantado un sistema de reconocimiento formal de la calidad. El 83% comprueba si cumplen o no con las especificaciones, el 68% dispone de un compromiso documental de cumplirlas y el 64% ha elaborado el listado con los valores concretos de especificaciones. El 55% conoce la existencia de unas especificaciones mínimas de la calidad consensuadas por el CEIEC. El 49% estaría de acuerdo en que estas especificaciones fueran preceptivas, mientras que el 33% no se define (AU)

Objectives: This work aims to determine the level of implementation of analytical quality specifications in Spanish clinical laboratories and, in particular, the minimum analytical quality specifications obtained by consensus of the Interdisciplinary Expert Committee on Quality Specifications (CEIEC) in the Clinical Laboratory, as well as to determine the opinions of the professionals as regards establishing mandatory analytical quality specifications.. Material and method: A questionnaire was designed including 4 descriptive, 16 retrospective, and 2 prospective questions. The responses were collected during September to November 2012. The requirement for participating was to be involved in an intercomparison program of any of the 4 Spanish scientific societies represented on the abovementioned committee. A total of 1,738 questionnaires were sent. Results: A total of 340 responses (19.6% over the total) were received. The results showed that 59% of respondents have a formally recognized quality system. The attainment of predefined specifications was checked by 83%, with 68% having a commitment for documented quality specifications, and 64% had made a list with specification values. A majority (55%) is aware of the existence of the consensus minimum quality specifications of the CEIEC, and 49% would agree that these specifications should become mandatory, while 33% did not declare a clear position on this subject (AU)

Preanalytical treatment of EDTA-anticoagulated blood to ensure stabilization of the mean platelet volume and component measured with the ADVIA counters.

The mean platelet component (MPC) parameter calculated by the ADVIA blood cell analyzers provides direct information on density, or granularity, of platelets and could become a useful biomarker to detect in vivo platelet activation. Unfortunately, it is largely affected by time and storage conditions in standard anticoagulants based on EDTA. The present study was designed to improve the stability of the MPC in blood specimens to facilitate a more standardized use in different laboratories. Blood from healthy controls was collected into EDTA plus additives, and stored at different conditions. MPC and the mean platelet volume (MPV) were assessed at 30 min and at 1, 3, 6 and 24hours after blood drawing on the ADVIA 2120 system. Flow cytometry was used to evaluate platelet-activation proteins. Ultrastructural morphology of platelets was assessed using electron microscopy. Storage in EDTA increased MPV, decreased MPC, reduced the number of alpha-granules, and induced changes in the phosphorylation patterns of platelet proteins. A solution based on EDTA containing wortmanin and tyrphostin (ED-WORTY), both inhibitors of signaling pathways, provided good stability for most of the parameters tested up to 6 hours at room temperature. Storage at lower temperatures produced more favorable results. ED-WORTY solutions preserved adequate morphology and had minimal influence on other parameters provided by the ADVIA 2120 system. Thus, the additives included in ED-WORTY may be useful for maintaining the stability of MPC for prolonged periods and to facilitate the transport and exchange of samples among institutions and laboratories.

Actualización de las especificaciones de la calidad analítica 2014. Consenso de las Sociedades Científicas nacionales / Updates of analytical quality specifications 2014. Consensus of national scientific societies

El objetivo de este estudio es calcular las especificaciones mínimas de la calidad (EMC) en bioquímica de orina, hemoglobina glucosilada en sangre y diversas determinaciones hematológicas, comparar estas especificaciones con las publicadas por organizaciones de diversos países y actualizar el listado con las 80 magnitudes estudiadas. Los materiales empleados en este estudio son todos los resultados de las EMC incluidas en los programas de garantía externa de la calidad organizadas por 4 sociedades científicas españolas, obtenidos desde 2007 hasta 2010. El número total de resultados obtenidos para hemoglobina glucosilada es de 13.054, para orina según cada magnitud va desde 14.180 (albúmina) hasta 20.594 (creatinina), y en hematología desde 1.839 (hemoglobina fetal) a 6.961 (antitrombina). Se concluye que cumplir la EMC de hemoglobina glucosilada no es suficiente para asegurar la calidad analítica según criterios clínicos, mientras que sí lo garantizan las EMC de orina; las magnitudes de hematología estudiadas en esta fase no pudieron compararse con especificaciones de obligado cumplimiento en otros países (no se encuentran publicadas), y algunas de ellas podrían requerir el cálculo de especificaciones diferentes para distintos niveles de concentración (AU)

The aim of this study is to calculate minimum quality specifications (MQS) in urine biochemistry, blood glycosylated hemoglobin and several hematological analytes, and to compare these specifications with those from other countries, as well as to update the values for the 80 analytes studied. Materials used in this work are the results from laboratories participating in the external quality assurance programs organized by four Spanish scientific societies, and obtained in the time period 2007-2010. A total of 13,054 results were obtained for glycosy-lated hemoglobin, and from 14,180 (albumin) to 20,594 (creatinine) for urine biochemistry, andfor hematology, from 1,839 (fetal hemoglobin) to 6,961 (antithrombin).The conclusions found were: to achieve the MQS for glycosylated hemoglobin does not ensure meeting clinical requirements, whereas MQS for urine biochemistry also meet the requirements based on biological variation. The MQS studied in this work could not be compared witht hose from other countries (there are no published values), and some of them could require calculations stratified according to several concentration levels (AU)