NEW YORK (Reuters Health) – With guidance and training, certain patients on long-term anticoagulant therapy can safely monitor their own INR levels and make dose adjustments as needed, with better outcomes (reductions in thromboembolic events and mortality) than usual clinic-based anticoagulation care, a meta-analytic review finds.
The observed mortality benefit is “impressive and similar to that observed for many currently accepted therapies in heart failure and acute coronary syndromes,” write the authors of a commentary that accompanies the analysis, published in Annals of Internal Medicine April 5.
In an email to Reuters Health, Dr. Hanna E. Bloomfield of the Minneapolis VA Medical Center cautioned that this self-care model “should only be recommended if the clinician’s office could offer the same degree of initial patient education employed in these studies, which was fairly intensive, and readily available access for patients who have questions.”
Several portable devices now available make it possible for patients to monitor their INR at home and either call in their results to their provider who makes medication dose adjustments or adjust the dose themselves.
The US Department of Veterans Affairs Evidence-based Synthesis Program, in conjunction with the VA’s Office of Quality and Performance, commissioned an analysis of published studies that compared patient self-testing (PST) and patient self-management (PSM) of anticoagulation therapy with usual care in a physician’s office or anticoagulation clinic.
Dr. Bloomfield and a panel of experts in anticoagulation management and delivery reviewed a total of 22 randomized controlled trials that enrolled a total of 8,413 community-dwelling adults on long-term anticoagulation therapy.
They found that patients randomly assigned to PST or PSM had a significant 26% lower risk of dying and a significant 42% reduction in major thromboembolic events, without any increased risk of major bleeding events.
The assumption, based on observational data, is that the better outcomes are the result of patient’s spending more time in the therapeutic range that is achieved with more frequent monitoring and dose adjustments, the study team notes.
The researchers also found evidence that patients were more satisfied and had improved quality of life when they self-managed their anticoagulant therapy.
However, this approach is not for everyone, Dr. Bloomfield and colleagues note in their article — a sentiment echoed in the accompanying commentary from Dr. Paul Anaya and Dr. David Moliterno of the Gill Heart Institute and University of Kentucky in Lexington.
Dr. Bloomfield’s team points out that in half of the trials they reviewed, fewer than 50% of potentially eligible patients successfully completed the training and agreed to be randomly assigned. They further note that these trials enrolled highly selected samples of patients who had the desire and confidence, as well as the manual dexterity, visual acuity and mental faculties to use the testing device and relay the information or correctly adjust doses on their own.
In addition, only five trials were considered “high quality” and only two were conducted in the United States; most were conducted in Europe, specifically Germany and the Netherlands. The study populations were largely homogenous (most involved white men) and many of the studies involved the use of coumarins other than warfarin. None of the studies addressed whether self-management is safe during the high-risk initiation phase.
Whether this self-care model for anticoagulation therapy can be successfully applied in typical US health care settings requires further study, conclude both the study team and the co-authors of the commentary.
Nonetheless, Drs. Anaya and Moliterno point out that this meta-analysis “confirms the findings from previous reports and reinforces the notion that in a highly motivated patient, a strategy of self-directed care of anticoagulation empowers the patient to become an active participant in his or her health care and can be safely and effectively implemented.”
“Should the clinical benefits of home INR testing and management reported in this meta-analysis continue to be realized, it is likely that this technology will soon join the ranks of other current self-directed care strategies, they conclude.
Ann Intern Med
