Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-4-20
pubmed:abstractText
The contribution of the thromboplastin international sensitivity index (ISI) to the interlaboratory coefficient of variation (CV) of the international normalised ratio (INR) with individual reagents was assessed. In theory the precision of the INR should increase with lower ISI values. An empirical relation has been established between the ISI, the INR, and its CV for two rabbit thromboplastins used in sufficient numbers for analysis in the United Kingdom. This was based on the cumulative data from the United Kingdom National External Quality Assessment Scheme (NEQAS) surveys over two years beginning in 1986. The actual precision achieved in NEQAS for the two reagents depends on the ISI value of the thromboplastin and it agreed closely with the figure predicted by the empirical model. The findings show that the ISI value of a thromboplastin strongly influences the interlaboratory variability of the INR obtained with it. The CV of the INR approximates to the CV of the prothrombin ratio multiplied by the ISI. Manufacturers of thromboplastin should therefore be encouraged to produce reagents showing good precision of results reported as simple prothrombin ratios and a low ISI value to avoid impairment in precision when ratio results are transformed to INR.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9746
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
92-6
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Effect of international sensitivity index (ISI) of thromboplastins on precision of international normalised ratios (INR)
pubmed:affiliation
United Kingdom Reference Laboratory for Anticoagulant Reagents and Control, Withington Hospital, Manchester.
pubmed:publicationType
Journal Article