The Home INR Study (THINRS)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Department of Veterans Affairs
ClinicalTrials.gov Identifier:
NCT00032591
First received: March 27, 2002
Last updated: March 18, 2014
Last verified: March 2014
  Purpose

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.


Condition Intervention Phase
Atrial Fibrillation
Procedure: Weekly patient self-testing of prothrombin time
Other: High quality anticoagulation management (HQACM) with conventional monthly testing
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: CSP #481 - The Home INR Study (THINRS)

Resource links provided by NLM:


Further study details as provided by Department of Veterans Affairs:

Primary Outcome Measures:
  • Time to First Event (Death, Stroke, Major Bleed) [ Time Frame: Time to event ] [ Designated as safety issue: Yes ]

    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 Below is the unpublished cumulative incidence information.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:
  • Time in Therapeutic Range Over Full Length of Follow-up (0 to 100 Percent) [ Time Frame: Full length of follow-up; average of 3 years ] [ Designated as safety issue: Yes ]
    Time in target range (TTR) based on Prothrombin Time standardized to the International Normalized Ratio

  • DASS at 2 Years of Follow-up [ Time Frame: At two years of follow-up ] [ Designated as safety issue: No ]
    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 [ Time Frame: After 2 years of follow-up for each subject ] [ Designated as safety issue: No ]
    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.

  • Health Care Costs at 2 Year [ Time Frame: After 2 years of follow-up for each subject ] [ Designated as safety issue: No ]

Enrollment: 2922
Study Start Date: August 2003
Study Completion Date: May 2008
Primary Completion Date: May 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Arm 1
Patient Self-Testing (PST) of prothrombin time by international normalized ratio (PT-INR or INR) with weekly testing
Procedure: Weekly patient self-testing of prothrombin time
Arm 2
High quality anticoagulation management (HQACM) with conventional monthly testing
Other: High quality anticoagulation management (HQACM) with conventional monthly testing
HQACM with testing every 4 weeks and as indicated for out of range values, medication/clinical changes.
Other Name: HQACM

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.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

To be enrolled in this study, patients must:

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

Exclusion Criteria:

Patients are excluded in this study if:

  1. 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
  2. subject enrolled in another randomized clinical trial that involves a drug or device intervention
  3. subject is not able to follow the protocol and all related instructions, and does not have a caregiver with these skills
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00032591

  Hide Study Locations
Locations
United States, Alabama
VA Medical Center, Birmingham
Birmingham, Alabama, United States, 35233
United States, California
VA Central California Health Care System, Fresno
Fresno, California, United States, 93703
VA Medical Center, Loma Linda
Loma Linda, California, United States, 92357
VA Palo Alto Health Care System
Palo Alto, California, United States, 94304-1290
VA Greater Los Angeles Healthcare System, West LA
West Los Angeles, California, United States, 90073
United States, Colorado
VA Eastern Colorado Health Care System, Denver
Denver, Colorado, United States, 80220
United States, Connecticut
VA Connecticut Health Care System (West Haven)
West Haven, Connecticut, United States, 06516
United States, Illinois
Edward Hines, Jr. VA Hospital
Hines, Illinois, United States, 60141-5000
VA Medical Center, North Chicago
North Chicago, Illinois, United States, 60064
United States, Iowa
VA Medical Center, Iowa City
Iowa City, Iowa, United States, 52246-2208
United States, Maryland
VA Maryland Health Care System, Baltimore
Baltimore, Maryland, United States, 21201
United States, Michigan
John D. Dingell VA Medical Center, Detroit
Detroit, Michigan, United States, 48201
United States, Minnesota
VA Medical Center, Minneapolis
Minneapolis, Minnesota, United States, 55417
United States, Missouri
VA Medical Center, Kansas City MO
Kansas City, Missouri, United States, 64128
United States, Nevada
Las Vegas
North Las Vegas, Nevada, United States, 89036
VA Sierra Nevada Health Care System
Reno, Nevada, United States, 89502
United States, New York
VA Medical Center, Bronx
Bronx, New York, United States, 10468
VA Western New York Healthcare System at Buffalo
Buffalo, New York, United States, 14215
VA Medical Center, Syracuse
Syracuse, New York, United States, 13210
United States, North Carolina
Durham VA Medical Center HSR&D COE
Durham, North Carolina, United States, 27705
United States, Ohio
VA Medical Center, Cleveland
Cleveland, Ohio, United States, 44106
United States, Oklahoma
VA Medical Center, Oklahoma City
Oklahoma City, Oklahoma, United States, 73104
United States, Pennsylvania
VA Pittsburgh Health Care System
Pittsburgh, Pennsylvania, United States, 15240
United States, Rhode Island
VA Medical Center, Providence
Providence, Rhode Island, United States, 02908
United States, Texas
VA North Texas Health Care System, Dallas
Dallas, Texas, United States, 75216
VA South Texas Health Care System, San Antonio
San Antonio, Texas, United States, 78229
United States, Virginia
VA Medical Center, Salem VA
Salem, Virginia, United States, 24153
United States, Wisconsin
Wlliam S. Middleton Memorial Veterans Hospital, Madison
Madison, Wisconsin, United States, 53705
Puerto Rico
VA Medical Center, San Juan
San Juan, Puerto Rico, 00921
Sponsors and Collaborators
Investigators
Study Chair: David B. Matchar, MD Durham VA Medical Center HSR&D COE
  More Information

Publications:
Responsible Party: Department of Veterans Affairs
ClinicalTrials.gov Identifier: NCT00032591     History of Changes
Other Study ID Numbers: 481
Study First Received: March 27, 2002
Results First Received: June 12, 2013
Last Updated: March 18, 2014
Health Authority: United States: Federal Government

Keywords provided by Department of Veterans Affairs:
AF
Mechanical heart valve (MHV)

Additional relevant MeSH terms:
Atrial Fibrillation
Arrhythmias, Cardiac
Cardiovascular Diseases
Heart Diseases
Pathologic Processes
Thrombin
Coagulants
Hematologic Agents
Hemostatics
Pharmacologic Actions
Therapeutic Uses

ClinicalTrials.gov processed this record on October 23, 2014