Clinical trial NCT00032591: The Home INR Study
Official title: CSP #481 - The Home INR Study (THINRS)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Atrial Fibrillation
Keywords: AF
Mechanical heart valve (MHV)
Lead sponsor: VA Office of Research and Development
Sponsor class: FED
First posted: 2002-03-28
Enrollment: 2922
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility 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

Primary outcomes:
measure: Time to First Event (Death, Stroke, Major Bleed)
timeFrame: Time to event
Secondary outcomes:
measure: Time in Therapeutic Range Over Full Length of Follow-up (0 to 100 Percent)
timeFrame: Full length of follow-up; average of 3 years
measure: DASS at 2 Years of Follow-up
timeFrame: At two years of follow-up
measure: Cumulative Gain in Health Utilities at 2 Year
timeFrame: After 2 years of follow-up for each subject
measure: Health Care Costs at 2 Year
timeFrame: After 2 years of follow-up for each subject
Other outcomes:
Locations:
city: Birmingham
country: United States
facility: VA Medical Center, Birmingham
state: Alabama
city: Fresno
country: United States
facility: VA Central California Health Care System, Fresno
state: California
city: Loma Linda
country: United States
facility: VA Medical Center, Loma Linda
state: California
city: Palo Alto
country: United States
facility: VA Palo Alto Health Care System
state: California
city: West Los Angeles
country: United States
facility: VA Greater Los Angeles Healthcare System, West LA
state: California
city: Denver
country: United States
facility: VA Eastern Colorado Health Care System, Denver
state: Colorado
city: West Haven
country: United States
facility: VA Connecticut Health Care System (West Haven)
state: Connecticut
city: Hines
country: United States
facility: Edward Hines, Jr. VA Hospital
state: Illinois
city: North Chicago
country: United States
facility: VA Medical Center, North Chicago
state: Illinois
city: Iowa City
country: United States
facility: VA Medical Center, Iowa City
state: Iowa
city: Baltimore
country: United States
facility: VA Maryland Health Care System, Baltimore
state: Maryland
city: Detroit
country: United States
facility: John D. Dingell VA Medical Center, Detroit
state: Michigan
city: Minneapolis
country: United States
facility: VA Medical Center, Minneapolis
state: Minnesota
city: Kansas City
country: United States
facility: VA Medical Center, Kansas City MO
state: Missouri
city: North Las Vegas
country: United States
facility: Las Vegas
state: Nevada
city: Reno
country: United States
facility: VA Sierra Nevada Health Care System
state: Nevada
city: Bronx
country: United States
facility: VA Medical Center, Bronx
state: New York
city: Buffalo
country: United States
facility: VA Western New York Healthcare System at Buffalo
state: New York
city: Syracuse
country: United States
facility: VA Medical Center, Syracuse
state: New York
city: Durham
country: United States
facility: Durham VA Medical Center HSR&D COE
state: North Carolina
city: Cleveland
country: United States
facility: VA Medical Center, Cleveland
state: Ohio
city: Oklahoma City
country: United States
facility: VA Medical Center, Oklahoma City
state: Oklahoma
city: Pittsburgh
country: United States
facility: VA Pittsburgh Health Care System
state: Pennsylvania
city: Providence
country: United States
facility: VA Medical Center, Providence
state: Rhode Island
city: Dallas
country: United States
facility: VA North Texas Health Care System, Dallas
state: Texas
city: San Antonio
country: United States
facility: VA South Texas Health Care System, San Antonio
state: Texas
city: Salem
country: United States
facility: VA Medical Center, Salem VA
state: Virginia
city: Madison
country: United States
facility: Wlliam S. Middleton Memorial Veterans Hospital, Madison
state: Wisconsin
city: San Juan
country: Puerto Rico
facility: VA Medical Center, San Juan
Study officials:
affiliation: Durham VA Medical Center HSR&D COE
name: David B. Matchar, MD
role: STUDY_CHAIR
References:
citation: Dolor RJ, Ruybalid RL, Uyeda L, Edson RG, Phibbs C, Vertrees JE, Shih MC, Jacobson AK, Matchar DB; THINRS Site Investigators. An evaluation of patient self-testing competency of prothrombin time for managing anticoagulation: pre-randomization results of VA Cooperative Study #481--The Home INR Study (THINRS). J Thromb Thrombolysis. 2010 Oct;30(3):263-75. doi: 10.1007/s11239-010-0499-8.
citation: Matchar DB, Jacobson A, Dolor R, Edson R, Uyeda L, Phibbs CS, Vertrees JE, Shih MC, Holodniy M, Lavori P; THINRS Executive Committee and Site Investigators. Effect of home testing of international normalized ratio on clinical events. N Engl J Med. 2010 Oct 21;363(17):1608-20. doi: 10.1056/NEJMoa1002617.
citation: Matchar DB, Jacobson AK, Edson RG, Lavori PW, Ansell JE, Ezekowitz MD, Rickles F, Fiore L, Boardman K, Phibbs C, Fihn SD, Vertrees JE, Dolor R. The impact of patient self-testing of prothrombin time for managing anticoagulation: rationale and design of VA Cooperative Study #481--the Home INR Study (THINRS). J Thromb Thrombolysis. 2005 Jun;19(3):163-72. doi: 10.1007/s11239-005-1452-0.
citation: Phibbs CS, Love SR, Jacobson AK, Edson R, Su P, Uyeda L, Matchar DB; writing for the THINRS Executive Committee and Site Investigators. At-Home Versus In-Clinic INR Monitoring: A Cost-Utility Analysis from The Home INR Study (THINRS). J Gen Intern Med. 2016 Sep;31(9):1061-7. doi: 10.1007/s11606-016-3700-8. Epub 2016 May 27.
citation: Matchar DB, Love SR, Jacobson AK, Edson R, Uyeda L, Phibbs CS, Dolor RJ. The impact of frequency of patient self-testing of prothrombin time on time in target range within VA Cooperative Study #481: The Home INR Study (THINRS), a randomized, controlled trial. J Thromb Thrombolysis. 2015 Jul;40(1):17-25. doi: 10.1007/s11239-014-1128-8.