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External quality assurance for heparin monitoring


Bonar, RA and Favaloro, EJ and Marsden, K, External quality assurance for heparin monitoring, Seminars in Thrombosis and Hemostasis, 38, (6) pp. 632-639. ISSN 0094-6176 (2012) [Contribution to Refereed Journal]

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DOI: doi:10.1055/s-0032-1321954


Although there is considerable debate regarding the usefulness of laboratory heparin monitoring, these test processes reflect a substantial portion of hemostasis laboratory activity. Accordingly, external quality assurance (EQA) remains an essential component of such testing, and ensures that laboratories provide the best available service for patient management. This report provides an overview of recent and past EQA related to heparin monitoring using data from the Royal College of Pathologists of Australasia Haematology Quality Assurance Program, and heparin-containing plasma samples with concentrations ranging from 0 to 1.4 U/mL. Laboratory tests evaluated comprised activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen, and anti-Xa assays. Results for APTT and TT testing were largely as expected, showing prolongation with increasing concentrations of heparin. Fibrinogen assays were generally unaffected by the presence of therapeutic heparin levels. Although cross-laboratory median values for the anti-Xa assay were close to target values, substantial interlaboratory variation in results, expressed as coefficient of variation (CV), was observed in all exercises conducted over an 8-year period (5 to 28% for low-molecular weight heparin [LMWH] and 19 to 37% for unfractionated heparin). Duplicate samples sent in consecutive surveys resulted in similar median values. The use of a survey-provided standard as assay calibrant improved CVs in earlier surveys, but not in the most recent survey.

Item Details

Item Type:Contribution to Refereed Journal
Keywords:activated partial thromboplastin time, anti-Xa assay, external quality assurance, low-molecular weight heparin, unfractionated heparin
Research Division:Biomedical and Clinical Sciences
Research Group:Clinical sciences
Research Field:Clinical chemistry (incl. diagnostics)
Objective Division:Health
Objective Group:Clinical health
Objective Field:Diagnosis of human diseases and conditions
UTAS Author:Marsden, K (Dr Katherine Marsden)
ID Code:85073
Year Published:2012
Web of Science® Times Cited:13
Deposited By:Research Division
Deposited On:2013-06-13
Last Modified:2017-04-11

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