Recomendaciones para el diseño e implementación de un programa de aseguramiento de la calidad de la fase preanalítica / Recommendations for the design and implementation of a Pre-analytical Phase Quality Assurance Program

El aseguramiento de la calidad de la fase preanalítica se orienta hacia 2 aspectos clave: la gestión de los errores preanalíticos desde la perspectiva de la seguridad del paciente, y la mejora y armonización de los procedimientos, basada en la aplicación de normativa además de recomendaciones profesionales. Al igual que el resto de las fases, debe incluir un programa interno de aseguramiento y la participación en programas de intercomparación entre laboratorios. El control de calidad interno debe basarse fundamentalmente en la identificación de riesgos, detección sistemática de errores y establecimiento de indicadores. La selección de los indicadores priorizando el impacto en el paciente, la forma de detectar y registrar los errores de forma sistemática y fácilmente explotable, así como las variables utilizadas en su cálculo, son aspectos importantes para medir la eficacia de las acciones de mejora y permitir la comparabilidad entre laboratorios. En este sentido, los programas externos de la calidad de la fase preanalítica basados en la comparación de indicadores, son una herramienta útil para el diseño e implantación de un programa de aseguramiento de la calidad. Este documento pretende servir de apoyo para que cada laboratorio seleccione, implante y evalúe sus propios indicadores, de acuerdo a las características individuales de sus procedimientos preanalíticos, pero sin perder de vista la armonización entre laboratorios

The quality assurance of the pre-analytical phase is oriented towards two key aspects; the management of pre-analytical errors from the perspective of patient safety, and the improvement and harmonisation of procedures, based on the application of regulations and professional recommendations. Like the rest of the phases, it should include an internal quality assurance program, as well as the participation in external quality assurance programs. The internal quality control should mainly be based on the identification of risks, systematic detection of errors, and establishment of indicators. The selection of indicators prioritising the impact on the patient, the way to detect and record errors in a systematic and easily exploitable manner, and also the variables used in the calculations, are important aspects to measure the effectiveness of improvement actions and to allow comparability between laboratories. In this sense, the external quality assurance programs of the pre-analytical phase based on the comparison of indicators are a useful tool for the design and implementation of a quality assurance program. This document is intended as a support for each laboratory to select, implement, and evaluate its own indicators, according to the individual characteristics of its pre-analytical procedures, but without losing sight of the harmonisation between laboratories

Tasa de filtrado glomerular estimada, eventos cardiovasculares y mortalidad por grupos de edad en individuos de 60 o más años del sur de Europa / Estimated glomerular filtration rate, cardiovascular events and mortality across age groups among individuals older than 60 years in Southern Europe

Introducción y objetivos: Los individuos con tasa de filtrado glomerular estimada (TFGe) disminuida tienen mayor riesgo de muerte por todas las causas (MT) y cardiovascular; se debate si los sujetos mayores con TFGe entre 45 y 59 ml/min/1,73 m2 también tienen un riesgo aumentado. Se evaluó la asociación entre la TFGe y la MT y los eventos cardiovasculares (ECV) en individuos de edad 60-74 y ≥ 75 años en un área de baja incidencia de enfermedad coronaria. Métodos: Se realizó un estudio retrospectivo de cohortes utilizando registros electrónicos de atención primaria y hospital. Se incluyó a 130.233 individuos de 60 o más años con una determinación de creatinina entre el 1 de enero de 2010 y el 31 de diciembre de 2011 y una TFGe según la fórmula de la Chronic Kidney Disease Epidemiology Collaboration. Las asociaciones independientes entre la TFGe y la MT y el ingreso por ECV se evaluaron mediante modelos de regresión de Cox y Fine-Gray respectivamente. Resultados: Media de edad, 70 años; el 56,1% eran mujeres. El 13,5% tenía una TFGe < 60 (el 69,7%, TFGe 45-59). Durante una mediana de seguimiento de 38,2 meses, 6.474 participantes fallecieron y 3.746 presentaron ECV. Tanto para la MT como para los ECV, las HR ajustadas de los participantes de 75 o más años fueron significativas con TFGe < 60. Con TFGe 45-59, para MT fueron HR = 1,61; IC95%, 1,37-1,89 y HR = 1,19; IC95%, 1,10-1,28 en los grupos de edad de 60-74 y ≥ 75 años respectivamente, y para ECV, HR = 1,28; IC95%, 1,08-1,51 y HR = 1,12; IC95%, 0,99-1,26. Conclusiones: En un área de baja incidencia de enfermedad coronaria, el riesgo de muerte y ECV fue de mayor a menor TFGe. A edades ≥ 75 años, la categoría de TFGe 45-59, en el límite significativo de ECV, incluyó a muchos individuos sin riesgo adicional significativo

Introduction and objectives: Individuals with a decreased estimated glomerular filtration rate (eGFR) are at increased risk of all-cause (ACM) and cardiovascular mortality; there is ongoing debate about whether older individuals with eGFR 45 to 59 mL/min/1.73 m2 are also at increased risk. We evaluated the association between eGFR and ACM and cardiovascular events (CVE) in people aged 60 to 74 and ≥ 75 years in a population with a low coronary disease incidence. Methods: We conducted a retrospective cohort study by using primary care and hospital electronic records. We included 130 233 individuals aged ≥ 60 years with creatinine measurement between January 1, 2010 and December 31, 2011; eGFR was estimated by using the Chronic Kidney Disease Epidemiology Collaboration creatinine equation. The independent association between eGFR and the risk of ACM and hospital admission due to CVE were determined with Cox and Fine-Gray regressions, respectively. Results: The median was age 70 years, and 56.1% were women; 13.5% had eGFR < 60 (69.7% eGFR 45-59). During a median follow-up of 38.2 months, 6474 participants died and 3746 had a CVE. For ACM and CVE, the HR in older individuals became significant at eGFR < 60. Fully adjusted HR for ACM in the eGFR 45 to 59 category were 1.61; 95%CI, 1.37-1.89 and 1.19; 95%CI, 1.10-1.28 in 60- to 74-year-olds and ≥ 75-year-olds, respectively; for CVE HR were 1.28; 95%CI, 1.08-1.51 and 1.12; 95%CI, 0.99-1.26. Conclusions: In a region with low coronary disease incidence, the risk of death and CVE increased with decreasing eGFR. In ≥ 75-year-olds, the eGFR 45 to 59 category, which had borderline risk for CVE, included many individuals without significant additional risk

Estimated Glomerular Filtration Rate, Cardiovascular Events and Mortality Across Age Groups Among Individuals Older Than 60 Years in Southern Europe.

INTRODUCTION AND OBJECTIVES: Individuals with a decreased estimated glomerular filtration rate (eGFR) are at increased risk of all-cause (ACM) and cardiovascular mortality; there is ongoing debate about whether older individuals with eGFR 45 to 59mL/min/1.73 m2 are also at increased risk. We evaluated the association between eGFR and ACM and cardiovascular events (CVE) in people aged 60 to 74 and ≥ 75 years in a population with a low coronary disease incidence. METHODS: We conducted a retrospective cohort study by using primary care and hospital electronic records. We included 130 233 individuals aged ≥ 60 years with creatinine measurement between January 1, 2010 and December 31, 2011; eGFR was estimated by using the Chronic Kidney Disease Epidemiology Collaboration creatinine equation. The independent association between eGFR and the risk of ACM and hospital admission due to CVE were determined with Cox and Fine-Gray regressions, respectively. RESULTS: The median was age 70 years, and 56.1% were women; 13.5% had eGFR < 60 (69.7% eGFR 45-59). During a median follow-up of 38.2 months, 6474 participants died and 3746 had a CVE. For ACM and CVE, the HR in older individuals became significant at eGFR < 60. Fully adjusted HR for ACM in the eGFR 45 to 59 category were 1.61; 95%CI, 1.37-1.89 and 1.19; 95%CI, 1.10-1.28 in 60- to 74-year-olds and ≥ 75-year-olds, respectively; for CVE HR were 1.28; 95%CI, 1.08-1.51 and 1.12; 95%CI, 0.99-1.26. CONCLUSIONS: In a region with low coronary disease incidence, the risk of death and CVE increased with decreasing eGFR. In ≥ 75-year-olds, the eGFR 45 to 59 category, which had borderline risk for CVE, included many individuals without significant additional risk.

Quality indicators for extra-analytical processes in clinical laboratory: ten years’ experience / Indicadores de calidad para los procesos extra-analíticos en el laboratorio clínico: 10 años de experiencia

Introduction. The selection and definition of quality indicators is essential for proper control of processes. This is not always easy, particularly with extra-analytical indicators, due to the complexity and degree of comparison of processes between laboratories, and the fact that data collection is not always automated. For this reason, the indicators and specifications need to be dynamic and re-designed in accordance with changes in the system. The aim of this paper is to describe the methodology used in the selection and definition of quality indicators, and their specifications for extra-analytical processes in public laboratories in Catalonia. Material and methods. During the study period (2004-2013), the members of the working group reported the mean annual value for each indicator, and the overall yearly mean of all participants was calculated. These results were compared and analyzed during periodic meetings, with regards to the pre-established specifications of the different laboratories. Results. Quality indicators and their specifications are presented. The evaluation of the validity of each quality indicator was made taking into account aspects including usefulness of the indicator in process monitoring, a clear definition, and a precise and reliable quantification. This methodology has made it possible to contrast the validity of the indicators or to reconsider the specification. Conclusions. The last 10 years’ experience of the Catalonian Health Institute Working Group on Quality Indicators in designing indicators and establishing quality specifications has proved very useful for improving the monitoring of processes in clinical laboratories included in the group (AU)

Introducción. La selección y definición de los indicadores de la calidad es imprescindible para controlar adecuadamente un proceso. Ello no siempre es fácil, sobre todo en el caso de los indicadores extraanalíticos, dada la complejidad y grado de comparabilidad de los procesos entre laboratorios y la necesaria recogida de datos que en muchas ocasiones no está automatizada. Asimismo, los indicadores y especificaciones deben ser dinámicos y rediseñarse en función de los cambios del sistema. El objetivo de este trabajo es describir la metodología utilizada en la selección y definición de indicadores de calidad y especificaciones para los procesos extraanalíticos en los laboratorios públicos de Cataluña. Material y métodos. Durante el período de estudio (2004-2013), los miembros del grupo han informado del valor medio anual para cada indicador, y se ha calculado la media anual de todos los participantes para cada uno de ellos. Estos resultados se han comparado y analizado a través de reuniones periódicas, con respecto a las especificaciones preestablecidas de los diferentes laboratorios. Resultados. Se presentan los indicadores de calidad y sus especificaciones. La evaluación de la validez de cada indicador de calidad se llevó a cabo teniendo en cuenta los aspectos incluyendo la utilidad del indicador en la supervisión de procesos, una definición clara y una cuantificación precisa y fiable. Esta metodología ha permitido contrastar la validez de los indicadores o reconsiderar la especificación. Conclusiones. Los últimos 10 años de experiencia del Grupo de Trabajo del Instituto Catalán de la Salud de Indicadores de Calidad en el diseño de indicadores y en establecer especificaciones de calidad ha demostrado ser muy útil para mejorar el seguimiento de los procesos en los laboratorios clínicos integrados en el grupo (AU)

Estimation of glomerular filtration rate by MDRD-4 IDMS and CKD-EPI in individuals of 60 years of age or older in primary care.

OBJECTIVE: To compare the prevalence and classification of chronic kidney disease (CKD) in accordance with the estimated glomerular filtration rate (eGFR) by MDRD-4 IDMS and CKD-EPI in individuals ≥ 60 years of age in primary care. MATERIAL AND METHODS: Cross-sectional descriptive observational study. Subjects ≥ 60 years treated at 40 primary care centres with serum creatinine determination conducted between 1 January and 31 December 2010 at a single centralised laboratory. EXCLUSION CRITERIA: renal transplantation, home care. VARIABLES: socio-demographic, anthropometric, risk factors and cardiovascular disease as recorded in electronic medical records and serum creatinine concentration by a standardised compensated kinetic Jaffe method with IDMS and eGFR by MDRD-4 IDMS and CKD-EPI. Agreement was analysed using the kappa coefficient and the Bland-Altman graphical method. RESULTS: 97,554 individuals (57.3% women, mean age 70.0 [Q1: 65.0, Q3: 77.0]). Median eGFR with MDRD 78.7 [66.7, 91.0] ml/min/1.73m² (77.9 for women, 79.7 for men, P<.001) and 81.8 [68.5, 90.5] ml/min/1.73 m² (P=.311) with CKD-EPI, eFG(MDRD) prevalence <60 15.0% (16.5% women, 13.1% men and 6.5% in ≤ 70 years, 24%> 70 years) with CKD-EPI 14.2% (15.0% female, 13.0% male, 4.7% in ≤ 70 years, 24.1% in> 70 years) . There was an overall agreement of 85.6% (kappa coefficient = 0.75) in women> 70 years of 86.6% (kappa = 0.77), of 83.2% (kappa = 0.69) in men> 70 years, of 82.7% (kappa = 0.68) in women ≤ 70 years and 90% (kappa = 0.81) in men ≤ 70 years. CONCLUSIONS: CKD-EPI decreased the prevalence of CKD especially in women ≤ 70 years; the prevalence increased in men> 70 years. One in eight individuals with stage 3a was reclassified to no disease; reclassified individuals had lower comorbidity.

Comunicación de valores críticos: resultados de una encuesta realizada por la comision de la calidad extraanalítica de la SEQC / Critical values reporting: results of a Spanish laboratories survey

Introducción. La detección y comunicación de valores críticos es una de las funciones del laboratorio que más repercusión tiene sobre la seguridad del paciente. La Comisión de la Calidad Extraanalítica de la SECQ ha realizado unas encuestas para conocer la situación de los laboratorios españoles. Material y métodos. Se enviaron dos encuestas a 728 laboratorios participantes en el Programa de Garantía Externa de la Calidad de Bioquímica suero, para conocer diferentes aspectos relacionados con la comunicación de los mismos y el límite establecido para diferentes magnitudes, diferenciando entre consulta externa y hospitalización. Resultados. La mayoría de los laboratorios encuestados tienen definidos valores críticos (81,5 %) y es el facultativo del laboratorio quien los notifica (87,3 %) telefónicamente (91,1 %) al médico responsable del paciente (86,6 %). Un 58 % de laboratorios comprueba que el aviso se ha recibido, un 54,8 % no ha definido el plazo de entrega y el 87,9 % no utiliza un indicador para controlar este proceso. Resultados. Las medianas obtenidas para la mayoría de constituyentes no difieren según el origen de los pacientes, siendo parecidas para consulta externa y hospitalización. Sin embargo, se encuentran diferencias en el nivel bajo del calcio y en el nivel alto de la creatinina, la glucosa y la urea. Conclusiones. Se observa una falta de estandarización y consenso en el tratamiento de estos valores. Debido a que su detección implica una actuación médica urgente, consideramos necesario que los laboratorios en colaboración con los clínicos desarrollen estrategias adecuadas para el establecimiento y notificación de estos valores (AU)

Introduction. Detection and reporting of critical values have great implications on patient safety. The SEQC Committee for the extra-analytical quality assessment has carried out a survey in order to evaluate these in Spanish laboratories. Material and methods. Two surveys were distributed among 728 participants registered in the External Quality Assessment Scheme (clinical chemistry, serum). Participants were asked to provide information regarding reporting of critical values and their decision limits. Outpatient and in-patient reporting were considered separately. Results. Most laboratories (81.5 %) had their critical values already defined; physicians assumed the responsibility of notifying critical results in 87.3 % of cases; critical results were mainly informed by telephone (91.1 %); 58 % of laboratories further verified that such notifications were received; delivery time was not taken into account in 54.8 % of laboratories; 87.9 % did not employ any indicator to track this process. Results. Median values obtained for most constituents did not differ and were similar for outpatient and hospital settings. Nevertheless, differences were found for the lower calcium critical value and for high critical values for creatinine, glucose and urea. Conclusions. Handling of critical values lacks standardization and a consensus among Spanish laboratories. Suitable strategies should be developed between laboratories and clinicians in order to correctly define and set up critical values, as their detection requires urgent medical action (AU)

Hemólisis en las muestras para diagnóstico / Hemolysis in diagnostic samples

La hemólisis es un efecto preanalítico evitable en la mayoría de los casos. Su aparición se debe a la técnica de extracción empleada y a las condiciones de transporte y preparación de las muestras. Su presencia produce error en muchas determinaciones habituales en química clínica, en muchos casos por la mezcla del contenido intraeritrocitario y en algún caso por el efecto interferente de componentes del hematíe, como la hemoglobina. En los laboratorios es necesario detectar y cuantificar la hemólisis en las muestras de forma estandarizada. La mayoría de los analizadores de bioquímica actuales incorporan sistemas de cuantificación espectrofotométrica de la hemoglobina. La influencia de la hemólisis en una magnitud depende de la metodología empleada, por lo que se debería solicitar a los fabricantes de equipos la realización de estudios y una información detallada sobre la influencia de la hemólisis en sus determinaciones, para que cada laboratorio pueda establecer el grado de hemólisis que supone error significativo para una magnitud, de acuerdo con sus especificaciones de calidad (AU)

In most cases, hemolysis is an avoidable preanalytical effect. It can appear as a result of the procedure used during blood specimen collection and also due to transport conditions and sample preparation. Hemolysis can lead to errors in many common determinations in clinical chemistry, mostly due to the leakage of cellular contents into the plasma, and in some cases, by the interfering effect of red blood cells components, such as hemoglobin. Laboratories need to be able to detect and measure hemolysis by a standardized procedure. The majority of current biochemistry analyzers can measure hemolysis by a spectrophotometric method. Nevertheless, the influence of hemolysis depends on the measurement method employed. Laboratories should demand that manufacturers give detailed information and make exhaustive studies regarding the influence of hemolysis on each analyte. This would allow each laboratory to establish the degree of hemolysis that produces a significant error in an analysis and in accordance with the laboratory's quality specifications (AU)

Multicentre physiological reference values for the concentration of creatininium in plasma and diagnostic specificity of glomerular filtration rate estimated with the MDRD equation.

BACKGROUND: The National Kidney Disease Education Program recommends that clinical laboratories, when asked for an estimation of glomerular filtration rate in a patient by means of the "four-variable" Modification of Diet in Renal Disease (MDRD) Study equation, also provide the measurement result for creatininium concentration in plasma and the appropriate reference interval. On the other hand, clinical laboratories seeking accreditation for compliance with ISO 15189:2003 need to demonstrate that the physiological reference intervals communicated to all users of laboratory services are appropriate for the patient population served, and for their measurement systems. METHODS: Ten clinical laboratories in different regions of Spain collaborated in identifying reference individuals and producing reference values for the concentration of creatininium in plasma using RD/Hitachi Modular Analytics analysers, and for the volume rate of glomerular filtrate in kidneys (glomerular filtration rate), estimated with the "four-variable" MDRD Study equation. All the logistic work was carried out in co-operation with the supplier of the reagents and analysers (Roche Diagnostics España, S.L., Sant Cugat del Vallès, Catalonia, Spain). Using all the reference values obtained by each laboratory, multicentre reference limits were estimated non-parametrically. RESULTS AND CONCLUSIONS: Reference intervals estimated in this study for concentrations of plasma creatininium are 52-85 micromol/L for women and 64-106 micromol/L for men. The diagnostic specificity of the estimated glomerular filtration rate is 99.2% when applied to healthy persons to screen for chronic kidney disease.

Multicentre physiological reference intervals for serum concentrations of immunoglobulins A, G and M, complement C3c and C4 measured with Tina-Quant reagents systems.

BACKGROUND: Clinical laboratories seeking accreditation for compliance with ISO 15189:2003 need to demonstrate that the physiological reference intervals communicated to all users of the laboratory service are appropriate for the patient population served and for the measurement systems used. In the case of immunological quantities, few articles have been published in peer-reviewed journals. METHODS: A total of 21 clinical laboratories in different regions of Spain collaborated in identifying reference individuals and determining adult reference intervals for some immunological quantities measured using RD/Hitachi Modular Analytics analysers and Tina-Quant reagent systems. These immunological quantities are the mass concentrations of immunoglobulin A, immunoglobulin G, immunoglobulin M, complement C3c and complement C4 in serum. All the logistic work was carried out in co-operation with the supplier of the reagents and analysers (Roche Diagnostics España, S.L., Sant Cugat del Vallès, Catalonia, Spain). From the set of reference values obtained by each laboratory, multicentre reference limits were estimated non-parametrically. RESULTS AND CONCLUSIONS: The reference intervals estimated in this study for concentrations of serum components under consideration are: complement C3c, 0.62-1.64 g/L for women and men; complement C4, 0.14-0.72 g/L for women and men; immunoglobulin A, 0.89-4.80 g/L for women and men; immunoglobulin G, 6.5-14.3 g/L for women and men; and immunoglobulin M, 0.48-3.38 g/L for women and 0.41-2.46 g/L for men.