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Patient Self Testing of Warfarin Therapy

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00594828
Recruitment Status : Unknown
Verified January 2008 by University College Cork.
Recruitment status was:  Active, not recruiting
First Posted : January 16, 2008
Last Update Posted : January 16, 2008
Hoffmann-La Roche
Health Research Board, Ireland
ZyCare Inc
Information provided by:
University College Cork

Brief Summary:
To test the hypothesis that home international normalised ratio (INR) monitoring with supervised patient self-testing (PST)can provide comparable or superior time in therapeutic range (TTR) to that provided by traditional outpatient anticoagulation.

Condition or disease Intervention/treatment Phase
Warfarin Device: CoaguChek (Patient self testing) Device: Anticoagulation Management Service (AMS) Phase 4

Detailed Description:

Indications for anticoagulant treatment to prevent thromboembolic disease have increased in recent years. INR must be monitored frequently to determine the safest dose and to minimize the risk for thrombotic and haemorrhagic complications. Standard warfarin therapy is associated with rates of major haemorrhage of up to 5-9% annually and recurrent venous thromboembolism of up to 8%. These event rates are dependent of the model of care used to manage warfarin therapy, with better outcomes associated with home testing of the INR which enables patients to monitor their response to warfarin more frequently. INR results must still be 'managed' by communicating the data to the healthcare provider, usually be telephone or fax.

In this study we will evaluate a novel method of PST; supervised PST with an internet based expert system, which 'manages' patients on oral anticoagulation by utilizing clinical and laboratory data provided by the patient and dose adjustment and retesting algorithms derived from clinical practice. Patients will be randomized to either 6 months of supervised PST or routine medical care by the AMS. At the end of the 6 month period, each patient will then 'cross over' to the other management regimen and the difference in TTR between the two periods will be compared.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 163 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Randomized Controlled Trial of Patient Self-Testing of Warfarin Therapy Using an Internet Based Expert System
Study Start Date : July 2006
Estimated Primary Completion Date : April 2009
Estimated Study Completion Date : April 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Blood Thinners

Arm Intervention/treatment
Experimental: 1
6 months of supervised patient self testing using an expert system
Device: CoaguChek (Patient self testing)
Patients will test their INR at home either biweekly, weekly or every 2 weeks using a CoaguChek point of care meter and communicate with the healthcare provider via an internet based expert system
Other Names:
  • CoaguChek S point of care meter
  • CoaguChek XS point of care meter
  • CoagCare expert system

Active Comparator: 2
6 months of routine medical care by the anticoagulation management service
Device: Anticoagulation Management Service (AMS)
Patients will attend the AMS for six months and have their INR checked every 4-6 weeks or more frequently, at the discretion of the clinician

Primary Outcome Measures :
  1. The primary outcome variable used to assess therapeutic efficacy and safety will be the difference in TTR during the six months of AMS management and the six months of PST [ Time Frame: 1 year ]

Secondary Outcome Measures :
  1. To compare the number of adverse events (haemorrhagic and thromboembolic) using PST and AMS management [ Time Frame: 1 year ]

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • on warfarin therapy for a minimum of 2 months
  • are expected to be on warfarin therapy for the duration of the 12 month study
  • internet access

Exclusion Criteria:

  • inability to provide informed consent
  • inability to use a home INR meter
  • patients who do not have a telephone
  • more than 2 missed clinic appointments in the preceding 6 months
  • patients on anticoagulant drugs other than warfarin (eg heparin, low molecular weight heparin)
  • history of hemorrhagic complications with a therapeutic or therapeutic INR in the preceding 6 months
  • inability to attend the hospital at short notice, if necessary

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00594828

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Cork University Hospital
Cork, Ireland
Sponsors and Collaborators
University College Cork
Hoffmann-La Roche
Health Research Board, Ireland
ZyCare Inc
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Principal Investigator: Susan J O'Shea, MD Cork University Hospital

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Responsible Party: Dr Susan O'Shea, University College Cork Identifier: NCT00594828    
Other Study ID Numbers: PA/05/16
First Posted: January 16, 2008    Key Record Dates
Last Update Posted: January 16, 2008
Last Verified: January 2008
Keywords provided by University College Cork:
Patient self-testing
Oral anticoagulation therapy
Expert Systems
Point-of-Care Systems
International Normalized Ratio
Additional relevant MeSH terms:
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