Effect of home testing of international normalized ratio on clinical events.
Abstract
<h4>Background</h4>Warfarin anticoagulation reduces thromboembolic complications in
patients with atrial fibrillation or mechanical heart valves, but effective management
is complex, and the international normalized ratio (INR) is often outside the target
range. As compared with venous plasma testing, point-of-care INR measuring devices
allow greater testing frequency and patient involvement and may improve clinical outcomes.<h4>Methods</h4>We
randomly assigned 2922 patients who were taking warfarin because of mechanical heart
valves or atrial fibrillation and who were competent in the use of point-of-care INR
devices to either weekly self-testing at home or monthly high-quality testing in a
clinic. The primary end point was the time to a first major event (stroke, major bleeding
episode, or death).<h4>Results</h4>The patients were followed for 2.0 to 4.75 years,
for a total of 8730 patient-years of follow-up. The time to the first primary event
was not significantly longer in the self-testing group than in the clinic-testing
group (hazard ratio, 0.88; 95% confidence interval, 0.75 to 1.04; P=0.14). The two
groups had similar rates of clinical outcomes except that the self-testing group reported
more minor bleeding episodes. Over the entire follow-up period, the self-testing group
had a small but significant improvement in the percentage of time during which the
INR was within the target range (absolute difference between groups, 3.8 percentage
points; P<0.001). At 2 years of follow-up, the self-testing group also had a small
but significant improvement in patient satisfaction with anticoagulation therapy (P=0.002)
and quality of life (P<0.001).<h4>Conclusions</h4>As compared with monthly high-quality
clinic testing, weekly self-testing did not delay the time to a first stroke, major
bleeding episode, or death to the extent suggested by prior studies. These results
do not support the superiority of self-testing over clinic testing in reducing the
risk of stroke, major bleeding episode, and death among patients taking warfarin therapy.
(Funded by the Department of Veterans Affairs Cooperative Studies Program; ClinicalTrials.gov
number, NCT00032591.).
Type
Journal articleSubject
THINRS Executive Committee and Site InvestigatorsHumans
Atrial Fibrillation
Myocardial Infarction
Thrombosis
Hemorrhage
Warfarin
Anticoagulants
Drug Monitoring
International Normalized Ratio
Self Care
Mortality
Follow-Up Studies
Prospective Studies
Heart Valve Prosthesis
Aged
Middle Aged
Female
Male
Stroke
Kaplan-Meier Estimate
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https://hdl.handle.net/10161/22910Published Version (Please cite this version)
10.1056/nejmoa1002617Publication Info
Matchar, David B; Jacobson, Alan; Dolor, Rowena; Edson, Robert; Uyeda, Lauren; Phibbs,
Ciaran S; ... THINRS Executive Committee and Site Investigators (2010). Effect of home testing of international normalized ratio on clinical events. The New England journal of medicine, 363(17). pp. 1608-1620. 10.1056/nejmoa1002617. Retrieved from https://hdl.handle.net/10161/22910.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Show full item recordScholars@Duke
Rowena Joy Dolor
Professor of Medicine
Rowena J. Dolor, MD, MHS did her medical training and internal medicine residency
at Duke University Medical Center. She completed the Ambulatory Care/Health Services
Research fellowship at the Durham VA Medical Center in 1996 and obtained her Masters
in Health Sciences degree in Biometry (renamed MHS in Clinical Research) from the
Duke University School of Medicine in 1998. Dr. Dolor was a staff physician in the
Ambulatory Care Service at the Durham VA Medical Center and Research Associate at
t
David Bruce Matchar
Professor of Medicine
My research relates to clinical practice improvement - from the development of clinical
policies to their implementation in real world clinical settings. Most recently my
major content focus has been cerebrovascular disease. Other major clinical areas in
which I work include the range of disabling neurological conditions, cardiovascular
disease, and cancer prevention. Notable features of my work are: (1) reliance on
analytic strategies such as meta-analysis, simulation, decision analy
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