The Home INR Study

Atrial Fibrillation Clinical Trial

— THINRS  

Official title:

CSP #481 - The Home INR Study (THINRS)

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00032591
• Other study ID #: 481
• Status: Completed
• Phase: Phase 4
• First received: March 27, 2002
• Last updated: March 18, 2014
• Start date: August 2003
• Est. completion date: May 2008

Study information

• Verified date: March 2014
• Source: VA Office of Research and Development
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Interventional

Clinical Trial 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.

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 information / eligibility

• Status: Completed
• Enrollment: 2922
• Est. completion date: May 2008
• Est. primary completion date: May 2008
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Atrial Fibrillation

Intervention

Procedure:
• Weekly patient self-testing of prothrombin time

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.

Locations

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

Sponsors (1)

Lead Sponsor	Collaborator
VA Office of Research and Development

Countries where clinical trial is conducted

United States,  Puerto Rico, 

References & Publications (3)

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 V — View 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 Oc — View 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 — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time to First Event (Death, Stroke, Major Bleed)	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.	Time to event	Yes
Secondary	Time in Therapeutic Range Over Full Length of Follow-up (0 to 100 Percent)	Time in target range (TTR) based on Prothrombin Time standardized to the International Normalized Ratio	Full length of follow-up; average of 3 years	Yes
Secondary	DASS at 2 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.	At two years of follow-up	No
Secondary	Cumulative Gain in Health Utilities at 2 Year	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.	After 2 years of follow-up for each subject	No
Secondary	Health Care Costs at 2 Year		After 2 years of follow-up for each subject	No