The Home INR Study

Phase 4

Completed

Conditions: Atrial Fibrillation

Interventions: Procedure: Weekly patient self-testing of prothrombin time
Other: High quality anticoagulation management (HQACM) with conventional monthly testing

Registration Number: NCT00032591

Lead Sponsor: US Department of Veterans Affairs

Brief Summary: Since home monitors of prothrombin time (PT) may potentially improve the safety, quality, and convenience of chronic anticoagulation management, it is likely that there will be demands from providers, patients, and manufacturers to make home monitors available to VA patients. The rationale for patient self-testing (PST) is that, compared to conventional high quality anticoagulation management (HQACM), it would permit more intense monitoring and increased patient participation in his/her own care, resulting in increased precision in anticoagulation control and thus fewer events of thromboembolism (strokes) and bleeding. The secondary hypothesis is that PST and HQACM will be comparable in terms of health care utilization and cost.

Detailed Description: Intervention: Weekly patient self-testing (PST) of prothrombin time by international normalized ratio (PT INR) versus conventional monthly high quality anticoagulation management (HQACM) from an anticoagulation clinic with a minimum two years follow-up.

Primary Hypothesis: Compared to conventional monitoring in the clinic, PST of anticoagulation intensity will decrease the number of events of thromboembolism (strokes), bleeding, and all cause deaths and improve the quality of anticoagulation.

Second Hypothesis: PST and conventional monitoring will be comparable in terms of health care utilization and cost.

Primary Outcomes: Event rates (thromboembolism or bleeding episodes), time to first event, time within therapeutic range for anticoagulation intensity, and total health care cost (including price of PST monitors) and utilization.

Study Abstract: Since home monitors of prothrombin time (PT) may potentially improve the safety, quality, and convenience of chronic anticoagulation management, it is likely that there will be demands from providers, patients, and manufacturers to make home monitors available to VA patients. The rationale for PST is that it would permit more intense monitoring and increased patient participation in his/her own care, resulting in increased precision in anticoagulation control and thus fewer events.

Original plan was for a study at 32 sites with a total sample size of about 3,200 patients and a length of three years (one for recruitment and two years of follow-up). Final status was 28 sites that randomized 2922 patients in 2.75 years of recruitment with a minimum of two years of follow-up.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 2922

Inclusion Criteria

To be enrolled in this study, patients must:

have AF and/or a MHV;
be scheduled to receive warfarin indefinitely (operationally defined as 2 years);
be using warfarin according to the criteria described in the Coumadin package insert (no off-label uses);
be expected to survive for the duration of the study;
not be suffering from intracranial bleeding (intracranial hemorrhage, subarachnoid hemorrhage, hemorrhagic stroke) or any other contraindication described in the Coumadin package insert;
be willing to perform PST;
be willing to be randomized;
possess adequate cognitive and language skills to follow the protocol and all related instructions;
be willing to participate for the full duration of the study;
sign the informed consent form; and
not be enrolled in another randomized clinical trial that involves a drug or device intervention.

Exclusion Criteria

Patients are excluded in this study if:

subject has had intracranial hemorrhage, subarachnoid hemorrhage, hemorrhagic stroke, or any other absolute/major contraindication described in the warfarin package insert within the last month
subject enrolled in another randomized clinical trial that involves a drug or device intervention
subject is not able to follow the protocol and all related instructions, and does not have a caregiver with these skills

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Arm 1	Weekly patient self-testing of prothrombin time	Patient Self-Testing (PST) of prothrombin time by international normalized ratio (PT-INR or INR) with weekly testing
Arm 2	High quality anticoagulation management (HQACM) with conventional monthly testing	High quality anticoagulation management (HQACM) with conventional monthly testing

Primary Outcome Measures

Name	Time	Method
Time to First Event (Death, Stroke, Major Bleed)	Time to event	Time to first event (death, stroke, major bleed) The primary outcome was time to first event, and we used the Kaplan-Meier method to compare survival curves and the results using the log-rank test. The number of patients with a primary outcome is what was reported in the NEJM paper. Below is the unpublished cumulative incidence information.

Secondary Outcome Measures

Name	Time	Method
Health Care Costs at 2 Year	After 2 years of follow-up for each subject
Time in Therapeutic Range Over Full Length of Follow-up (0 to 100 Percent)	Full length of follow-up; average of 3 years	Time in target range (TTR) based on Prothrombin Time standardized to the International Normalized Ratio
DASS at 2 Years of Follow-up	At two years of follow-up	Satisfaction with care was quantified using the Duke Anticoagulation Satisfaction Scale (DASS). Scores range from 25 to 225, with lower scores indicating higher satisfaction.
Cumulative Gain in Health Utilities at 2 Year	After 2 years of follow-up for each subject	Scores range from -0.36 to 1.00 per year, with a negative score indicating a state worse than being dead and a score of 1.00 indicating perfect health. Since the time frame is 2 years, the range is -0.72 to 2.00.

Trial Locations

Locations (29): VA Greater Los Angeles Healthcare System, West LA
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West Los Angeles, California, United States
VA Medical Center, Iowa City
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Iowa City, Iowa, United States
VA Maryland Health Care System, Baltimore
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Baltimore, Maryland, United States
VA Medical Center, Kansas City MO
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Kansas City, Missouri, United States
VA Medical Center, Providence
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Providence, Rhode Island, United States
VA Medical Center, Bronx
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Bronx, New York, United States
Edward Hines, Jr. VA Hospital
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Hines, Illinois, United States
Wlliam S. Middleton Memorial Veterans Hospital, Madison
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Madison, Wisconsin, United States
VA Medical Center, Salem VA
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Salem, Virginia, United States
VA Central California Health Care System, Fresno
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Fresno, California, United States
VA Medical Center, Syracuse
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Syracuse, New York, United States
Durham VA Medical Center HSR&D COE
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Durham, North Carolina, United States
VA Medical Center, Loma Linda
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Loma Linda, California, United States
VA Medical Center, Minneapolis
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Minneapolis, Minnesota, United States
VA Sierra Nevada Health Care System
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Reno, Nevada, United States
VA Medical Center, Cleveland
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Cleveland, Ohio, United States
VA Pittsburgh Health Care System
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Pittsburgh, Pennsylvania, United States
VA South Texas Health Care System, San Antonio
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San Antonio, Texas, United States
VA North Texas Health Care System, Dallas
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Dallas, Texas, United States
VA Eastern Colorado Health Care System, Denver
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Denver, Colorado, United States
John D. Dingell VA Medical Center, Detroit
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Detroit, Michigan, United States
VA Medical Center, Oklahoma City
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Oklahoma City, Oklahoma, United States
VA Medical Center, Birmingham
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Birmingham, Alabama, United States
VA Palo Alto Health Care System
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Palo Alto, California, United States
VA Medical Center, North Chicago
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North Chicago, Illinois, United States
VA Western New York Healthcare System at Buffalo
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Buffalo, New York, United States
VA Medical Center, San Juan
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San Juan, Puerto Rico
VA Connecticut Health Care System (West Haven)
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West Haven, Connecticut, United States
Las Vegas
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North Las Vegas, Nevada, United States