Establishing Pediatric Reference Intervals: A Challenging Task

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Strategies to define performance specifications in laboratory medicine: 3 years on from the Milan Strategic Conference

Measurements in clinical laboratories produce results needed in the diagnosis and monitoring of patients. These results are always characterized by some uncertainty. What quality is needed and what measurement errors can be tolerated without jeopardizing patient safety should therefore be defined and specified for each analyte having clinical use. When these specifications are defined, the total examination process will be "fit for purpose" and the laboratory professionals should then set up rules to control the measuring systems to ensure they perform within specifications. The laboratory community has used different models to set performance specifications (PS). Recently, it was felt that there was a need to revisit different models and, at the same time, to emphasize the presuppositions for using the different models. Therefore, in 2014 the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) organized a Strategic Conference in Milan. It was felt that there was a need for more detailed discussions on, for instance, PS for EQAS, which measurands should use which models to set PS and how to set PS for the extra-analytical phases. There was also a need to critically evaluate the quality of data on biological variation studies and further discussing the use of the total error (TE) concept. Consequently, EFLM established five Task Finish Groups (TFGs) to address each of these topics. The TFGs are finishing their activity on 2017 and the content of this paper includes deliverables from these groups

Misidentification and Other Preanalytical Errors

Misidentification and Other Preanalytical Errors The largest number of laboratory errors occur in the preanalytical phase and are mainly due to educational and organizational reasons. The experience of our institution, as well as the results of an Italian interlaboratory effort to detect and reduce errors/risk of errors in laboratory medicine will be illustrated

Automation in urinalysis: evaluation of three urine test strip analysers

A clinical laboratory evaluation was conducted on the Clinitek Auto 2000, the Super Aution Analyzer and the Urotron RL9 for the determination of glucose, protein, pH, blood, ketone-bodies and bilirubin

Multicentre evaluation of the Monarch (IL) clinical chemistry analyser

A multicentre evaluation of the Monarch centrifugal analyser is reported. Precision, linearity and accuracy were assessed by comparison with routine methods. Calibration stability, photometric and dispensing accuracy, and carry-over related to samples and reagents were also evaluated. The overall performance of the instrument was good, showing an excellent photometric and dispensing accuracy, absence of sample-dependent carry-over, and almost negligible reagent carry-over. Good precision, linearity and correlation with routine methods were found for the parameters tested. The instrument is reliable and is now used as the routine clinical chemistry analyser in two of the three laboratories taking part in the evaluation

Urinary neutrophil gelatinase-associated lipocalin as an early predictor of prolonged intensive care unit stay after cardiac surgery.

Neutrophil gelatinase-associated lipocalin (NGAL) is a protein of lipocalin family highly expressed in various pathologic states and is an early biomarker of acute kidney injury in cardiac surgery. We performed an observational study to evaluate the role of NGAL in predicting postoperative intensive care stay in high-risk patients undergoing cardiac surgery. We enrolled 27 consecutive patients who underwent high-risk cardiac surgery with cardiopulmonary bypass. Urinary NGAL (uNGAL) was measured before surgery, at intensive care unit (ICU) arrival and 24 h later. Univariate and multivariate predictors of ICU stay were performed. uNGAL was 18.0 (8.7–28.1) ng/mL at baseline, 10.7 (4.35–36.0) ng/mL at ICU arrival and 29.6 (9.65–29.5) 24 h later. The predictors of prolonged ICU stay at the multivariate analysis were body mass index (BMI), uNGAL 24 h after surgery, and aortic cross-clamp time. The predictors of high uNGAL levels 24 h after at a multivariate analysis were preoperative uNGAL and logistic European System for Cardiac Operative Risk Evaluation. At a multivariate analysis the only independent predictors of prolonged ICU stay were BMI, uNGAL 24 h after surgery and aortic cross-clamp time

Global FT4 immunoassay standardization: an expert opinion review.

Abstract Objectives Results can vary between different free thyroxine (FT4) assays; global standardization would improve comparability of results between laboratories, allowing development of common clinical decision limits in evidence-based guidelines. Content We summarize the path to standardization of FT4 assays, and challenges associated with FT4 testing in special populations, including the need for collaborative efforts toward establishing population-specific reference intervals. The International Federation of Clinical Chemistry and Laboratory Medicine Committee for Standardization of Thyroid Function Tests has undertaken FT4 immunoassay method comparison and recalibration studies and developed a reference measurement procedure that is currently being validated. Further studies are needed to establish common reference intervals/clinical decision limits. Standardization of FT4 assays will change test results substantially; therefore, a major education program will be required to ensure stakeholders are aware of the benefits of FT4 standardization, planned transition procedure, and potential clinical impact of the changes. Assay recalibration by manufacturers and approval process simplification by regulatory authorities will help minimize the clinical impact of standardization. Summary Significant progress has been made toward standardization of FT4 testing, but technical and logistical challenges remain. Outlook Collaborative efforts by manufacturers, laboratories, and clinicians are required to achieve successful global standardization of the FT4 assays

Reference Intervals: Strengths, Weaknesses, and Challenges

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Within- and between-subject biological variation data for tumor markers based on the European Biological Variation Study

Postponed access: the file will be available after 2022-05-10Objectives: Reliable biological variation (BV) data are required for the clinical use of tumor markers in the diagnosis and monitoring of treatment effects in cancer. The European Biological Variation Study (EuBIVAS) was established by the EFLM Biological Variation Working Group to deliver BV data for clinically important measurands. In this study, EuBIVAS-based BV estimates are provided for cancer antigen (CA) 125, CA 15-3, CA 19-9, carcinoembryonic antigen, cytokeratin-19 fragment, alpha‐fetoprotein and human epididymis protein 4. Methods: Subjects from five European countries were enrolled in the study, and weekly samples were collected from 91 healthy individuals (53 females and 38 males; 21–69 years old) for 10 consecutive weeks. All samples were analyzed in duplicate within a single run. After excluding outliers and homogeneity analysis, the BVs of tumor markers were determined by CV-ANOVA on trend-corrected data, when relevant (Røraas method). Results: Marked individuality was found for all tumor markers. CYFRA 21-1 was the measurand with the highest index of individuality (II) at 0.67, whereas CA 19-9 had the lowest II at 0.07. The CV I s of HE4, CYFRA 21-1, CA 19-9, CA 125 and CA 15-3 of pre- and postmenopausal females were significantly different from each other. Conclusions: This study provides updated BV estimates for several tumor markers, and the findings indicate that marked individuality is characteristic. The use of reference change values should be considered when monitoring treatment of patients by means of tumor markers.publishedVersio