Send to

Choose Destination
See comment in PubMed Commons below
Am J Clin Pathol. 2005 Feb;123(2):184-8.

Clinical impact of point-of-care vs laboratory measurement of anticoagulation.

Author information

Cardiology, Pharmaceutical Sciences Clinical Service Unit, Vancouver General Hospital, BC, Canada.


Patients using anticoagulation point-of-care (POC) monitors are advised to periodically test these systems against laboratory methods to monitor performance. The international normalized ratio (INR), however, can vary between test systems owing to different instrument-reagent combinations. In a randomized study evaluating warfarin self-management, we compared INR measured by patients on a POC monitor (ProTime, International Technidyne Corporation, Edison, NJ) with those obtained at a hospital laboratory within 1 hour Ninety-one paired INR determinations from 55 patients met inclusion criteria. Clinical agreement in which POC and laboratory INR were within or outside the target INR range occurred in 56 (62%) of 91 cases (kappa = 0.35). The mean (SD) difference between POC and laboratory INR was 0.44 (0.61). Six pairs differed by 1 or more INR units, 3 at study initiation resulting in POC monitor replacement. The accuracy of INR self-testing with ProTime was acceptable. The small failure rate of INR agreement might be clinically important, suggesting the need for external quality control systems.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center