Resumen
Introducción
La aportación del Laboratorio Clínico en el ámbito diagnóstico es cada día mas importante porque gran parte de las decisiones clínicas que se adoptan se basan en nuestros ...resultados.
Contenido
La cuantificación en sangre de hormona paratiroidea (PTH) presenta una importante variabilidad analítica debido a la heterogeneidad de sus formas circulantes y a la configuración antigénica de los diferentes métodos disponibles. Esta circunstancia puede tener impacto en aquellas situaciones patológicas que cursan con valores circulantes de PTH excesivamente elevados, como sucede en la enfermedad renal crónica (ERC).
Resumen
A pesar de la identificación de otras moléculas involucradas en las alteraciones óseas y minerales asociadas a la ERC, como el klotho o el factor fibroblástico 23, los nefrólogos siguen basando sus decisiones terapéuticas en la PTH; el problema es que, el desconocimiento de estos aspectos analíticos en su cuantificación, puede inducir a errores en la interpretación clínica de sus resultados.
Perspectiva
Esta revisión aborda estas consideraciones desde el Laboratorio Clínico y plantea posibles estrategias futuras, que afectan tanto a la elección del método como a la expresión de los resultados de PTH, con la finalidad de acercarnos más a la realidad del paciente renal, en colaboración con el nefrólogo.
The purpose of this study is to understand the evolution of the analytical performance of the laboratories participating in the Spanish society of laboratory medicine (SEQC
) external quality ...assurance (EQA) programmes during its 30 years of operation and to compare it with the performance of other EQA programmes to establish whether the results are similar. The results obtained during this period are evaluated by applying the biological variability (BV) and state of the art-derived quality specifications. In addition, the results are compared with those obtained by other EQA programme organisations. It is noted that the laboratories participating in the EQA–SEQC
programmes have improved their performance over 30 years of experience and that the specifications derived from biological variation are achievable. It is difficult to compare EQA programmes, due to lack of accessibility and the differences in the design of these programmes (control materials, calculations used and analytical specifications established). The data from this study show that for some biological magnitudes the results obtained by the programmes are not yet harmonised, although efforts are being made to achieve this. Organisers of EQA programmes should also join the harmonisation effort by providing information on their results to enable comparison.
Standardization is the ability to obtain interchangeable results leading to same medical interpretation. External quality assessment (EQA) is the main support of the on-going harmonization ...initiatives. Aim of study was to evaluate results obtained from two years category 1 EQA program experience in Spain and determine the impact of applying this type of EQA program on the analytical standardization.
According to the analytical method, traceability and instrument different groups were established which results were evaluated by calculating mean, coefficient of variation and percent of deviation to the reference value. Analytical performance specifications used to the results' evaluation were derived from biological variation for bias and from the inter-laboratory coefficients of variation found in a previous pilot study.
Only creatinine measured by enzymatic methods gave excellent results, although few laboratories used this method. Creatine kinase and GGT gave good precision and bias in all, but one instrument studied. For the remaining analytes (ALT, ALP, AST, bilirubin, calcium, chloride, glucose, magnesium, potassium, sodium, total protein and urate) some improvement is still necessary to achieve satisfactory standardization in our setting.
The two years of category 1 EQA program experience in Spain have manifested a lack of standardization of 17 most frequent biochemistry tests used in our laboratories. The impact of the information obtained on the lack of standardization is to recommend abandoning methods such as ALT, AST without exogenous pyridoxal phosphate, Jaffe method for creatinine, and do not use non-commutable calibrators, such as aqueous solutions for calcium and sodium.
Internal quality control – past, present and future trends Ricós, Carmen; Fernandez-Calle, Pilar; Perich, Carmen ...
Advances in Laboratory Medicine / Avances en Medicina de Laboratorio,
10/2022, Letnik:
3, Številka:
3
Journal Article
Recenzirano
Odprti dostop
This paper offers an historical view, through a summary of the internal quality control (IQC) models used from second half of twentyth century to those performed today and wants to give a projection ...on how the future should be addressed.
The material used in this work study are all papers collected referring IQC procedures. The method used is the critical analysis of the different IQC models with a discussion on the weak and the strong points of each model.
First models were based on testing control materials and using multiples of the analytical procedure standard deviation as control limits. Later, these limits were substituted by values related with the intended use of test, mainly derived from biological variation. For measurands with no available control material methods based on replicate analysis of patient' samples were developed and have been improved recently; also, the sigma metrics that relates the quality desired with the laboratory performance has resulted in a highly efficient quality control model. Present tendency is to modulate IQC considering the workload and the impact of analytical failure in the patent harm.
This paper remarks the strong points of IQC models, indicates the weak points that should be eliminated from practice and gives a future projection on how to promote patient safety through laboratory examinations.
Abstract Objectives Despite clinical guidelines do not recommend the use of point-of-care testing (POCT) glucometers for diagnostic purposes yet, the analytical performance is continuously improving. ...Thus, we evaluate the technical accuracy and clinical concordance of POCT glucometers during an oral glucose tolerance test (OGTT) in children for prediabetes and diabetes diagnosis in a comparison study. Methods Pediatric patients with an OGTT indication who attended the Diabetes Unit between December 2020 and September 2021 were recruited for this prospective observational study. During the functional test, glycaemia was immediately measured in venous blood using two glucometers (unconnected and connected) and sent to the central laboratory. Results The study included 98 patients. There was a high correlation between the glucometers and the central laboratory (Pearson correlation coefficient=0.912 and 0.950, for unconnected and connected glucometer, respectively). The median OGTT turnaround time (TAT) was significantly decreased (connected glucometer: 2.02 h interquartile range, 2.00–2.07, central laboratory: 11.63 h 6.09–25.80), with similar overall cost. The diagnostic concordance between connected glucometer and the central laboratory was 71.1 % (95 % confidence interval (CI) 61.5–79.2). The clinical decision would have been the same in the 92.8 % of the cases, but treatment would have not been indicated in 4 patients (4.1 %). Conclusions POCT glucometers have demonstrated a high correlation and an acceptable diagnostic concordance with the central laboratory during an OGTT, as well the connected device offers a significant decrease in TAT, without increasing costs. However, as severe clinical impact could happen, POCT glucometers may not be used for diagnosis yet.
Biological variation (BV) data have many fundamental applications in laboratory medicine. At the 1st Strategic Conference of the European Federation of Clinical Chemistry and Laboratory Medicine ...(EFLM) the reliability and limitations of current BV data were discussed. The EFLM Working Group on Biological Variation is working to increase the quality of BV data by developing a European project to establish a biobank of samples from healthy subjects to be used to produce high quality BV data.
The project involved six European laboratories (Milan, Italy; Bergen, Norway; Madrid, Spain; Padua, Italy; Istanbul, Turkey; Assen, The Netherlands). Blood samples were collected from 97 volunteers (44 men, aged 20-60 years; 43 women, aged 20-50 years; 10 women, aged 55-69 years). Initial subject inclusion required that participants completed an enrolment questionnaire to verify their health status. The volunteers provided blood specimens once per week for 10 weeks. A short questionnaire was completed and some laboratory tests were performed at each sampling consisting of blood collected under controlled conditions to provide serum, K2EDTA-plasma and citrated-plasma samples.
Samples from six out of the 97 enroled subjects were discarded as a consequence of abnormal laboratory measurements. A biobank of 18,000 aliquots was established consisting of 120 aliquots of serum, 40 of EDTA-plasma, and 40 of citrated-plasma from each subject. The samples were stored at -80 °C.
A biobank of well-characterised samples collected under controlled conditions has been established delivering a European resource to enable production of contemporary BV data.
Resumen
Objetivos
Los resultados de los programas de garantía externa de la calidad se evalúan frente a especificaciones generalmente basadas en los datos de variación biológica (VB). En este trabajo ...se pretende comprobar, por un lado, si el cumplimiento de especificaciones varía con la aplicación de nuevos valores de VB y, por otro lado, señalar qué patologías estarían comprometidas debido a una prestación analítica poco satisfactoria de sus mensurandos clave.
Métodos
El material utilizado son los resultados de los programas externos de la SEQC
ML
desde 2015 hasta 2022. El método es estimar la desviación del resultado individual respecto al valor diana considerado y calcular el porcentaje de resultados que cumplen la especificación pre-establecida.
Resultados
En 97 de los 133 mensurandos el cumplimiento se mantiene entre el 80 y el 100 % de los resultados obtenidos en los dos períodos estudiados. En 23 mensurandos el grado de cumplimiento oscila entre el 51 y el 79 % en los dos periodos. En ALT, AST y sodio el grado de cumplimiento es igual o menor al 50 % de los resultados en el primer período, quedando en este grupo únicamente el sodio en el segundo período.
Conclusiones
Para la mayoría de los mensurandos estudiados el cumplimiento se mantiene independiente de la especificación empleada (SEQC
ML
o EFLM). Los resultados de ion sodio están por debajo del valor diana, por lo que podrían darse casos de diagnóstico falso de hiponatremia. Los métodos de picrato alcalino no compensado sobreestiman la creatinina, pudiendo ocasionar falsa información de insuficiencia renal.
ObjectivesDiabetes mellitus intensify the risks and complications related to COVID-19 infection. A major effect of the pandemic has been a drastic reduction of in-person visits. The aim of this study ...was to evaluate the impact of the COVID-19 pandemic on HbA1c management and results among pediatric and adult outpatients with diabetes, considering the laboratory and point-of-care testing (POCT) HbA1c measurements. MethodsObservational retrospective study including patients from pediatric and adult diabetes units was conducted. HbA1c results obtained in the laboratory and POCT over 3 years (2019-2021) were collected from the laboratory information system. ResultsAfter the lockdown, the number of HbA1c plummeted. Children returned soon to routine clinical practice. The number of HbA1c increased gradually in adults, especially in POCT. Globally, HbA1c results were lower in children compared with adults (p<0.001). HbA1c values in children (p<0.001) and adults (p=0.002) decreased between pre-pandemic and post-pandemic periods, though lower than the HbA1c reference change value. The percentage of HbA1c results above 8% remained stable during the study period. ConclusionsContinuous glucose monitoring and a telemedicine have been crucial, even allowing for improvements in HbA1c results. During the lockdown, patients with better metabolic control were managed in the laboratory whereas patients with poorer control or a severe clinical situation were attended in diabetes units by POCT. Adults returned to pre-pandemic management slowly because they were more susceptible to morbidity and mortality due to COVID-19. Coordination among all health professionals has been essential to offering the best management, especially in difficult scenarios such as the COVID-19 pandemic.
El objetivo de este estudio es conocer la evolución de la prestación analítica de los laboratorios participantes en los programas EQA de la SEQCML durante los 30 años de funcionamiento y compararla ...con la prestación obtenida en otros programas EQA para saber si los resultados son similares.
ObjectivesNumerous biological variation (BV) studies have been performed over the years, but the quality of these studies vary. The objectives of this study were to perform a systematic review and ...critical appraisal of BV studies on glycosylated albumin and to deliver updated BV estimates for glucose and HbA1c, including recently published high-quality studies such as the European Biological Variation study (EuBIVAS). MethodsSystematic literature searches were performed to identify BV studies. Nine publications not included in a previous review were identified; four for glycosylated albumin, three for glucose, and three for HbA1c. Relevant studies were appraised by the Biological Variation Data Critical Appraisal Checklist (BIVAC). Global BV estimates were derived by meta-analysis of BIVAC-compliant studies in healthy subjects with similar study design. ResultsOne study received BIVAC grade A, 2B, and 6C. In most cases, the C-grade was associated with deficiencies in statistical analysis. BV estimates for glycosylated albumin were: CVI=1.4% (1.2-2.1) and CVG=5.7% (4.7-10.6), whereas estimates for HbA1c, CVI=1.2% (0.3-2.5), CVG=5.4% (3.3-7.3), and glucose, CVI=5.0% (4.1-12.0), CVG=8.1% (2.7-10.8) did not differ from previously published global estimates. ConclusionsThe critical appraisal and rating of BV studies according to their methodological quality, followed by a meta-analysis, generate robust, and reliable BV estimates. This study delivers updated and evidence-based BV estimates for glycosylated albumin, glucose and HbA1c.
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