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Thromb Haemost 2000; 83(05): 698-703
DOI: 10.1055/s-0037-1613895
Review Article
Schattauer GmbH

A Comparison of Point-of-Care Instruments Designed for Monitoring Oral Anticoagulation with Standard Laboratory Methods

Robert Gosselin
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
,
John T. Owings
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
,
Richard H. White
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
,
Rose Hutchinson
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
,
Jennifer Branch
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
,
Kathy Mahackian
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
,
Marilyn Johnston
2   Hamilton Civic Hospitals Research Centre, Hamilton, Ontario, Canada
,
Edward C. Larkin
1   From the University of California, Davis Medical Center, Sacramento, CA, USA
› Author Affiliations
Further Information

Publication History

Received 13 April 1999

Accepted after resubmission 21 January 2000

Publication Date:
08 December 2017 (online)

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Summary

Our study compared point-of-care (POC) device monitoring with traditional clinical laboratory methods device of patients on oral anticoagulant therapy. The POC devices used in the study were Coumatrak, CoaguChek, CoaguChek Plus, Thrombolytic Assessment System (TAS) PT-One, TAS PTNC, TAS PT, Hemachron Jr. Signature, Protime Microcoagulation System, and Medtronics ACT II. The clinical laboratory method used thromboplastins with different ISI values: Innovin and Thromboplastin C Plus (TPC). All POC INRs showed strong correlation with both laboratory methods, with correlation coefficients of >0.900. All POC methods demonstrated a significant (p <0.05) difference in INR values, except the TAS PTNC and ACT II INRs (p: 0.12 and 0.71 respectively) when compared with Innovin INRs. All POC INRs were significantly different from TPC generated INRs (p <0.05). Comparisons of the POC INRs to the group mean of the POC methods, show higher correlation (R>0.93), but there were still significant (p<0.05) differences noted between the POC group INR mean and CoaguChek Plus, ACT II, TAS PT-One, TAS PTNC, and Hemachron Jr Signature INRs. These data indicate that POC INR biases exist between laboratory methods and POC devices. Until a suitable whole blood INR standardization method is available, we conclude that clinicians using point-of-care anticoagulation monitoring should be aware of differences between POC and parent laboratory values.

Key words

International Normalized Ratio (INR) - point-of-care devices - coumadin monitoring
 

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