Effect of home testing of international normalized ratio on clinical events.

Abstract

Background

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.

Methods

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).

Results

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).

Conclusions

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.).

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1056/nejmoa1002617

Publication Info

Matchar, David B, Alan Jacobson, Rowena Dolor, Robert Edson, Lauren Uyeda, Ciaran S Phibbs, Julia E Vertrees, Mei-Chiung Shih, et al. (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.

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Scholars@Duke

Matchar

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 analysis and cost-effectiveness analysis; (2) a balancing of methodological rigor the needs of medical professionals; and (3) dependence on interdisciplinary groups of experts.
This approach is best illustrated by the Stroke Prevention Patient Outcome Research Team (PORT), for which I served as principal investigator. Funded by the AHCPR, the PORT involved 35 investigators at 13 institutions. The Stroke PORT has been highly productive and has led to a stroke prevention project funded as a public/private partnership by the AHCPR and DuPont Pharma, the Managing Anticoagulation Services Trial (MAST). MAST is a practice improvement trial in 6 managed care organizations, focussing on optimizing anticoagulation for individuals with atrial fibrillation.
I serve as consultant in the general area of analytic strategies for clinical policy development, as well as for specific projects related to stroke (e.g., acute stroke treatment, management of atrial fibrillation, and use of carotid endarterectomy.) I have worked with AHCPR (now AHRQ), ACP, AHA, AAN, Robert Wood Johnson Foundation, NSA, WHO, and several pharmaceutical companies.
Key Words: clinical policy, disease management, stroke, decision analysis, clinical guidelines

Dolor

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 the Center for Health Services Research in Primary Care at the Durham VAMC from 1995-2012.  She is currently an investigator of several federally-funded projects conducted in the community-based setting. Dr. Dolor served as a member of the AHRQ PBRN Resource Center Steering Committee and co-chaired the NAPCRG PBRN conference from 2012-2016.

Since 1996, Dr. Dolor has been the director of the Primary Care Research Consortium (PCRC), a network of primary care practices in the Duke University Health System and outlying communities. The PCRC has participated in over 100 industry- and investigator-initiated studies on hypertension, hyperlipidemia, asthma, otitis, obesity, diabetes, depression, anticoagulation, and vaccines. In 2002, the Duke PCRC received grant funding from the Agency for Healthcare Research and Quality (AHRQ) for Primary Care Practice-based Research Networks (PBRNs). The focus of her research pertains to primary care clinical and outcomes research. She has helped lead a number of comparative effectiveness studies and large, pragmatic trials in the primary care setting.   In addition, Dr. Dolor has led or co-led networks in otolaryngology and integrative medicine.

Dr. Dolor has contributed to the development and methodology of Practice-based Research Networks (PBRNs). She has served as a co-investigator on three online resources to help researchers conduct multi-center research in the primary care practice-based setting – (1) A toolkit for building and sustaining health research partnership with practices and communities, http://www.researchtoolkit.org/index.php (2) Toolkit for Developing and Conducting Multi-site Clinical Trials in Practice Based Research Networks, http://www.dartnet.info/ClinicalTrialsPBRNToolkit.htm ; and (3) PBRN Research Good Practices (PRGP), http://www.napcrg.org/PBRNResearchGoodPractice

From July 2009-June 2012, she served as the Associate Director for the Duke EPC. She worked closely with the Director, Gillian Sanders PhD, in overseeing the day-to-day functioning of EPC projects and supervising EPC personnel.  The Duke EPC was awarded a contract entitled “American Recovery and Reinvestment Act of 2009: Comprehensive EPC Comparative Effectiveness Reviews for Effective Health Care” to serve within a core group of EPCs to focus on a comprehensive approach to comparative effectiveness review (CER) and evidence synthesis. The Duke EPC area of concentration was cardiovascular and pulmonary disorders.

She previously served as the principal investigator for the systematic literature review for the AHA Scientific Statement: Evidence-based guidelines for cardiovascular disease prevention in women published in 2004 and updated in 2007. She was the PI of four CER projects on “Noninvasive Technologies for the Diagnosis of Coronary Artery Disease in Women” and “Treatment Strategies for Women with CAD”, “PAD”, and “UA/NSTEMI” as well as upcoming CER topics on pulmonary arterial hypertension, peripheral artery disease and unstable angina/non-ST elevation myocardial infarction. 

Within the Duke Clinical and Translational Institute (CTSI), Dr. Dolor directs the collaboration with CTSI researchers on community-based PBRN projects. From 2011- 2014, she was co-chair of the CTSA PBRN Collaboration Workgroup, and a member of the Community Engagement Key Function Committee, the CTSA Strategic Goal 4 Combined Networking Group committee, and the CTSA Comparative Effectiveness Research Key Function Committee (CER KFC). Since September 2016, she serves as a Co-chair of the Dissemination, Implementation and Knowledge Transfer Workgroup within the Collaboration Engagement Domain Task Force.

In the fall of 2014, Dr. Dolor joined Vanderbilt part-time as a Consultant/Adjunct Associate Professor of Medicine within the Division of General Internal Medicine. Her role is to assist in the formation of the Meharry-Vanderbilt Clinical Research Network, a PBRN in the mid-Tennessee region.  In addition, she is a co-investigator on the Mid-South Clinical Data Research Network, a PCORnet awardee, to build the partnership with the community practices for comparative effectiveness studies that will utilize the electronic health records/information system infrastructure of the CDRN. 




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