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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
10
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pubmed:dateCreated |
1994-11-7
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pubmed:abstractText |
Data collected in a national external quality assessment program for free thyroxine (fT4) and free triiodothyronine (fT3) were analyzed to evaluate the performance of 10 method/kits with 26 control samples distributed to approximately 170 laboratories. The control materials were normal serum pools, pooled sera supplemented with thyroid hormones, a pregnancy serum pool, serum pooled from patients with familial dysalbuminemic hyperthyroxinemia (FDH), and a normal serum pool progressively diluted. The between-laboratory variability (CV) was approximately constant in normal and supplemented pools for fT4 (15.3%) and fT3 (24.0%) but markedly increased in diluted, pregnancy, and FDH pools (21.9-35.2% for fT4 and 28.6-66.5% for fT3) because of increases in systematic between-kit differences in control samples with altered binding-protein capacity. Moreover, free hormone concentrations measured in progressively diluted sera averaged lower than in undiluted samples. This decrease of concentration was less for back-titration or labeled-antibody techniques and greater for labeled-analog methods; only the method involving adsorption to cross-linked dextran (Sephadex) was unaffected by dilution. Evaluation of the reproducibility of the method/kits showed between-assay, between-laboratory precision ranging from 7.8% to 17.0% for fT4 and from 9.8% to 20.3% for fT3.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0009-9147
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
40
|
pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1956-61
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:7923779-Female,
pubmed-meshheading:7923779-Humans,
pubmed-meshheading:7923779-Immunoassay,
pubmed-meshheading:7923779-Laboratories,
pubmed-meshheading:7923779-Pregnancy,
pubmed-meshheading:7923779-Quality Control,
pubmed-meshheading:7923779-Reagent Kits, Diagnostic,
pubmed-meshheading:7923779-Reproducibility of Results,
pubmed-meshheading:7923779-Sensitivity and Specificity,
pubmed-meshheading:7923779-Thyroxine,
pubmed-meshheading:7923779-Triiodothyronine
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pubmed:year |
1994
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pubmed:articleTitle |
Systematic differences between commercial immunoassays for free thyroxine and free triiodothyronine in an external quality assessment program.
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pubmed:affiliation |
CNR-Institute of Clinical Physiology, Pisa, Italy.
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pubmed:publicationType |
Journal Article,
Comparative Study
|