Clinical trial NCT00594828: Patient Self Testing of Warfarin Therapy
Official title: Randomized Controlled Trial of Patient Self-Testing of Warfarin Therapy Using an Internet Based Expert System
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE4
Conditions: Warfarin
Keywords: Patient self-testing
Oral anticoagulation therapy
Expert Systems
Point-of-Care Systems
International Normalized Ratio
Lead sponsor: University College Cork
Sponsor class: OTHER
Collaborators: name: Hoffmann-La Roche
name: Health Research Board, Ireland
name: ZyCare Inc
First posted: 2008-01-16
Enrollment: 163
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: 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
timeFrame: 1 year
Secondary outcomes:
measure: To compare the number of adverse events (haemorrhagic and thromboembolic) using PST and AMS management
timeFrame: 1 year
Other outcomes:
Locations:
city: Cork
country: Ireland
facility: Cork University Hospital
Study officials:
affiliation: Cork University Hospital
name: Susan J O'Shea, MD
role: PRINCIPAL_INVESTIGATOR
References: