Performance evaluation of the new hematology analyzer UniCel DxH 900.

INTRODUCTION: UniCel DxH900 (Beckman Coulter, Miami, Florida, USA) is a quantitative, multi-parameter, automated hematology analyzer for in vitro diagnostic use in clinical laboratories. The aim of this study was to evaluate the analytical performance of the new DxH900 analyzer to verify its diagnostic and clinical utility in the hematology laboratory of a tertiary care hospital in Spain. The most important and novel feature offered by DxH900 analyzer is providing MDW (monocyte distribution width), a new hematologic parameter which is being clinically validated as an early sepsis indicator with promising results. METHODS: We evaluated imprecision (including MDW), linearity, and carryover of DxH900. Method comparison for cell blood count (CBC) was performed in relation to DxH800 with 100 samples. We compared leukocyte differential (DIFF) from DxH900 with manual 400-cell differential. 390 samples were assessed for flag performance. RESULTS: Results obtained for between days and within-run imprecision were good. DxH900 showed excellent linearity (R = 1.00) over analytical range for white blood cells, red blood cells, hemoglobin, platelets, and reticulocyte count (RET) (R = 0.96) and no significant carryover effect. CBC and RET on the DxH900 correlated well with DxH800 (R ≥ 0.99). Comparison with manual differential showed excellent correlation (R ≥ 0.88), except for basophils. Flagging performance exhibited sensitivity over 90% for majority of alarm messages and very high negative predictive value (over 95%). CONCLUSION: UniCel DxH900 Coulter analyzer provides reliable results and fully comparable to DxH800. DxH900 is an accurate, highly precise analyzer with good analytical performances to be used effectively in high-volume laboratories.

Reaching consensus on communication of critical laboratory results using a collective intelligence method.

BACKGROUND: There is no consensus in the literature about what analytes or values should be informed as critical results and how they should be communicated. The main aim of this project is to establish consensual standards of critical results for the laboratories participating in the study. Among the project's secondary objectives, establishing consensual procedures for communication can be highlighted. METHODS: Consensus was reached among all participating laboratories establishing the basis for the construction of the initial model put forward for consensus in conjunction with the clinicians. A real-time Delphi, methodology "health consensus" (HC), with motivating and participative questions was applied. The physician was expected to choose a numeric value within a scale designed for each analyte. RESULTS: The medians of critical results obtained represent the consensus on critical results for outpatient and inpatient care. Both in primary care and in hospital care a high degree of consensus was observed for critical values proposed in the analysis of creatinine, digoxin, phosphorus, glucose, international normalized ratio (INR), leukocytes, magnesium, neutrophils, chloride, sodium, calcium and lithium. For the rest of critical results the degree of consensus obtained was "medium high". The results obtained showed that in 72% of cases the consensual critical value coincided with the medians initially proposed by the laboratories. CONCLUSIONS: The real-time Delphi has allowed obtaining consensual standards for communication of critical results among the laboratories participating in the study, which can serve as a basis for other organizations.

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)

The use of pleural fluid sCD44v6/std ratio for distinguishing mesothelioma from other pleural malignancies.

OBJECTIVE: Differentiating metastatic adenocarcinoma from malignant pleural mesothelioma is often a challenging task. Spliced forms of CD44, such as exon v6 (CD44v6), have been implicated in tumor metastasis. We examined the diagnostic performance of soluble (s) CD44v6 and CD44 standard (sCD44std) as biomarkers for nonmesothelioma pleural malignancies in a retrospective series. METHODS: The pleural fluid from 161 patients with pleural effusion (33 mesotheliomas, 104 nonmesothelioma malignancies, and 24 benign conditions) was analyzed for sCD44v6 and sCD44std levels using an enzyme-linked immunosorbent assay kit. The ability of sCD44v6 and sCD44std levels and the sCD44v6/std ratio for distinguishing mesothelioma from nonmesothelioma malignancy were examined. RESULTS: Median pleural fluid concentrations of sCD44v6 but not sCD44std were significantly higher in patients with nonmesothelioma malignancy (101.5 ng/mL) than in those with mesothelioma (38 ng/mL, p < 0.0001). Fluids from metastatic squamous cell carcinomas exhibited particularly high sCD44v6 levels (388 ng/mL). A cutoff value of 100 ng/mL had the highest accuracy for distinguishing mesothelioma from nonmesothelioma malignancy (sensitivity 53% and specificity 88%) or metastatic adenocarcinoma (sensitivity 60% and specificity 88%). An sCD44v6/std ratio of more than 0.34 discriminated between adenocarcinoma and mesothelioma with a sensitivity of 60%, a specificity of 93%, a likelihood ratio positive of 9.97, and an area under the curve of 0.87 (95% confidence interval: 0.80-0.94). CONCLUSIONS: The pleural fluid sCD44v6/std ratio may be a new diagnostic marker in the differential diagnosis between primary mesothelioma and other pleural malignancies. Values greater than 0.34 predict nonmesothelioma malignancy and may be a help in determining whether an invasive thoracoscopy is necessary.