External quality assessment (EQA) for CoaguChek monitors

Joergen Jespersen; Leon Poller; A. M. H. P. van den Besselaar; Felix J. M. van der Meer; Gualtiero Palareti; Armando Tripodi; Caroline Shiach; Michelle Keown; Saied Ibrahim

doi:10.1160/TH09-10-0683

Thrombosis and Haemostasis, Table of Contents

Thromb Haemost 2010; 103(05): 936-941
DOI: 10.1160/TH09-10-0683

Theme Issue Article

Schattauer GmbH

External quality assessment (EQA) for CoaguChek monitors

Authors

Joergen Jespersen

¹Department of Clinical Biochemistry, Hospital of South West Denmark, Esbjerg and Department for Thrombosis Research, Institute of Public Health, University of Southern Denmark, Esbjerg, Denmark
Leon Poller

²EAA Central Facility, Faculty of Life Sciences, University of Manchester, Manchester, UK
A. M. H. P. van den Besselaar

³Department of Thrombosis and Haemostasis, Leiden University Medical Center, Leiden, The Netherlands
Felix J. M. van der Meer

⁴Department of Thrombosis and Haemostasis, Leiden University Medical Center, Thrombosis Service Leiden, Leiden, The Netherlands
Gualtiero Palareti

⁵Department of Angiology and Blood Coagulation, University Hospital Sant’Orsola-Malpighi, Bologna, Italy
Armando Tripodi

⁶University and IRCCS Maggiore Hospital, Mangiagalli and Regina Elena Foundation, Milan, Italy
Caroline Shiach

⁷Department of Haematology, Manchester Royal Infirmary, Oxford Road, Manchester, UK
Michelle Keown

²EAA Central Facility, Faculty of Life Sciences, University of Manchester, Manchester, UK
Saied Ibrahim

²EAA Central Facility, Faculty of Life Sciences, University of Manchester, Manchester, UK

Abstract

Summary

Anticoagulant control facilities are being overwhelmed by requests for monitoring and large numbers of patients are not therefore receiving treatment. Procedures designed for point-of-care testing have therefore been developed, the most popular being the CoaguChek. The need for external quality assessment (EQA) of monitors used by patients in self-management has been stressed in a European Commission (EC) Directive. It would not however be feasible for all CoaguChek monitors to be enrolled in national or regional EQA schemes which take time to organise and analyse. The European Concerted Action on Anticoagulation (ECAA) has therefore evolved a simpler system. Its value has been assessed in collaboration with the European Concerted Action on Thrombosis (ECAT). 523 monitors were tested at nine clinics which asked patients to bring their CoaguChek instruments to be assessed with the ECAA/ECAT procedure based on a set of 5 plasma samples with certified international normalised ratios (INR). 15% or more deviation from the certified INR on a single certified plasma sample from the set was defined by the ECAA as the limit of acceptable performance. One hundred and six (20.3%) of the monitors tested showed significant deviation and higher than average incidence of significant INR deviations reported with one specific numbered lot of test strips. Recent ECAA/ECAT, Danish and Italian studies report regular EQA of CoaguChek monitors is essential. There is general agreement that this should be performed at reasonably frequent intervals, at six months or whenever there is a change of the manufacturer’s test strips.

Keywords

Oral anticoagultaion - external quality assessment - point-of-care monitors - INR deviation - accuracy, precision

Full Text

References

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