Precisely Wrong? Urinary Fractionated Metanephrines and Peer-Based Laboratory Proficiency Testing
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چکیده
منابع مشابه
Precisely wrong? Urinary fractionated metanephrines and peer-based laboratory proficiency testing.
Hilden lists some of these limitations in his letter; another important one is its global interpretation, which does not translate well into clinical practice (1 ). The partial area under the ROC curve in the clinically relevant range of false-positive rates, or falsenegative rates, is a useful alternative measure of inherent diagnostic accuracy. Dr. Hilden advocates performance measures that i...
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CONTEXT The initial diagnosis of pheochromocytoma relies on plasma fractionated metanephrines levels. Normal levels exclude pheochromocytoma, but positive tests have a low positive predictive value due to the disease's rarity. OBJECTIVES The objective of the study was to evaluate three approaches to distinguish between true-positive and false-positive tests: 1) increased cutoff for plasma fra...
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Laboratories offering a quality service for the microbiological examination of food must implement a quality assurance system. An effective system should, in addition to daily quality control of procedures, consumables, and equipment, include external laboratory accreditation to a recognised standard, the use of validated test methods, and participation in an external quality assessment (profic...
متن کاملStability of urinary fractionated metanephrines and catecholamines during collection, shipment, and storage of samples.
BACKGROUND Measurements of 24-h fractionated urinary metanephrines and catecholamines are used for the diagnosis of pheochromocytoma, but adequate information is needed regarding collection, storage, and shipment conditions. METHODS Spot urine samples were collected from 8 healthy volunteers. Aliquots were immediately frozen at -20 degrees C, or acidified to pH 4 and then frozen either direct...
متن کاملThe role of urinary fractionated metanephrines in the diagnosis of phaeochromocytoma
BACKGROUND & OBJECTIVES Plasma and urinary metanephrines are used as screening tests for the diagnosis of phaeochromocytoma. The recommended cut-off levels are not standardized. This study was conducted to identify a cut-off level for 24 h urinary fractionated metanephrines viz. metanephrine (uMN) and normetanephrine (uNMN) using enzyme immunoassay for the diagnosis of phaeochromocytoma. METH...
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ژورنال
عنوان ژورنال: Clinical Chemistry
سال: 2005
ISSN: 0009-9147,1530-8561
DOI: 10.1373/clinchem.2004.043802