1,721,087 research outputs found
Obtaining reference intervals traceable to reference measurement systems : it is possible, who is responsible, what is the strategy ?
No full textAn issue associated with standardization efforts is the need
to develop useful reference intervals (RI). Lack of proper RI may hamper the implementation of standardization in
Laboratory Medicine as standardization can modify analyte results and, without adequate RI, this can impair the result
interpretation. Once defi ned, RI obtained with analytical procedures
that produce results traceable to the corresponding reference system can be transferred among laboratories, providing that they use commercial assays that produce results
traceable to the same reference system and populations have the same characteristics. Multicenter studies are needed for a robust defi nition of traceable RI, using experimental protocols that include well defi ned prerequisites. Particularly,
employed methods must produce results that are traceable to the reference system for that specifi c analyte. Thus, the trueness of laboratories producing reference values should
be verifi ed and, if necessary, experimental results corrected
in accordance with correlation results with the selected reference.
If requirements in the adoption of traceable RI are fulfi lled, the possibility of providing RI that are applicable to any laboratory, able to produce results traceable to the reference system, is realistic. The defi nition of traceable RI should
hopefully cause the disappearance of different RI employed for the same analyte, providing more effective information to clinicians
I risultati dei miei esami sono normali? : considerazioni su intervalli di riferimento e livelli decisionali
No full textIn this editorial, we look at the topic of reference intervals from the point of view of the patient or the clinician, discussing differences between the concept of reference intervals (a biological characteristic of a well defined population) and the various types of decision limits. Decision limits can be defined in different ways, e.g. based on Bayesian approach, on pathophysiological studies or on clinical experience (i.e. by consensus), but always they differ from reference intervals, because, while the latter deal with biology, decision limits are related to some kind of clinical decision and defined behaviour by clinicians
Performance evaluation of Arkray HA-8190V system for measuring glycated hemoglobin
No full textIntroduction: the new fully automated HPLC ion-exchange system ADAMS A1c HA-8190V analyzer, developed by ARKRAY Inc., running in two different modes (Variant and Fast) has been evaluated.
Methods: reproducibility was evaluated according to the EP-15A3 standard. Method comparison was performed on 122 fresh blood samples, according to the EP-9 standard. The system was compared to 3 other HPLC analyzers, based on ion-exchange (Tosoh G11 and Bio-Rad D-100) and boronate affinity chromatography (Trinity Biotech Premier Hb9210). Usability was evaluated by using to a score evaluation system.
Results: reproducibility proved to be very good at normal and high HbA1c concentration, with total CVs always <0.7 %, when HbA1c was expressed in mmol/mol as well as in % units. The HA-8190V system was well correlated to the other HPLC analyzers, with a mean bias not clinically relevant. Finally, the usability of the system was evaluated and proved to be well acceptable.
Conclusions: the ARKRAY HA-8190 V system was found to be a reliable and suitable method for routine HbA1c measurement in clinical chemistry laboratories
Establishing Reliable Pediatric Percentiles of Serum Liver Enzyme Concentrations Cannot Ignore the Employed Methodology
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Standardizzazione in enzimologia clinica : una sfida per la teoria della riferibilità metrologica
No full textStandardization in clinical enzymology: a challenge for the theory of metrological traceability. The goal of standardization for measurements of catalytic concentrations of enzymes is to achieve comparable results in human samples, independent of the reagent kits, instruments, and laboratory where the assay is carried out. To pursue this objective, the IFCC has established reference measurement systems for the most important clinical enzymes. These systems are based on the following requirements: a) reference methods, well described in procedures that are extensively evaluated; b) suitable reference materials; and c) reference laboratories operating in a highly controlled manner. Using these reference systems appropriately, the diagnostic industry can assign traceable values to commercial calibrators. Clinical laboratories, which use routine procedures with validated calibrators to measure human specimens, can finally obtain values which are traceable to higher-order reference procedures. These reference systems constitute the structure of the traceability chain to which the routine methods can be linked via an appropriate calibration process, provided that they have a comparable specificity (i.e., they are measuring the same catalytic quantity)
Teoria e pratica degli intervalli di riferimento riferibili
No full textTheory and practice of traceable reference intervals. An issue associated with standardization efforts is the need to develop useful reference intervals. Lack of proper reference intervals may indeed hamper the implementation of standardization in Laboratory Medicine as standardization can modify analyte results and, without adequate reference intervals, this can impair the result interpretation. Once defined, reference intervals obtained with analytical procedures that produce results traceable to the corresponding reference system can be transferred among laboratories, providing that they use commercial assays that produce results traceable to the same reference system and populations have the same characteristics. Multicenter studies are needed for a robust definition of traceable reference intervals, using experimental protocols that include well defined prerequisites. Particularly, employed methods must produce results that are traceable to the reference system for that specific analyte. Thus, the trueness of laboratories producing reference values should be verified and, if necessary, experimental results corrected in
accordance with correlation results with the selected reference. If requirements in the adoption of traceable reference intervals are fulfilled, the possibility of providing reference intervals that are applicable to any laboratory, able to produce results traceable to the reference system, is realistic. The definition of traceable reference intervals should
hopefully cause the disappearance of different reference intervals employed for the same analyte, providing more
effective information to clinicians
La qualità del risultato di laboratorio: fonti di variabilità, modalità di valutazione e stima del loro impatto clinico
No full textLa qualità del risultato di laboratorio: fonti di variabilità, modalità di valutazione e stima del loro impatto clinico
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