Weekly Coagulation Self-testing among Warfarin Patients Significantly Improves Outcomes, According to Study Published in the American Journal of Managed Care

Results Show Highest Rate of Control Ever Observed with Warfarin in Real-world Setting, Surpassing Thresholds for Cost-Effectiveness of Newer Agents Identified in Five Recent Independent Studies

Mar 24, 2014, 09:12 ET from Alere Inc.

WALTHAM, Mass., March 24, 2014 /PRNewswire/ -- Alere Inc. (NYSE: ALR) today announced the publication of the largest-ever study of warfarin patient self-testing, which demonstrated that weekly International Normalized Ratio (INR) testing significantly improves control of warfarin, as measured by time in therapeutic range (TTR), versus a variable testing frequency. Results of the Self-Testing Analysis Based on Long-Term Experience (STABLE) study, which was supported by Alere, were published today in The American Journal of Managed Care.  

In the retrospective analysis of patients self-testing results which were taken between January 2008 and June 30, 2011, more than 4,500 warfarin patients who self-tested weekly achieved a mean TTR of 74 percent for up to 2.5 years of evaluation. This represents the greatest and longest level of control ever observed in either clinical trials or in real-world settings and demonstrates weekly self-testing to be a significant advance in the safety of warfarin. Dangerously high or low test results can increase patient risk of major bleeding seven fold and stroke four fold.[1,2]

"The STABLE results dramatically demonstrate the importance of regular and frequent self-testing as an adjunct to warfarin therapy, and bring important information to bear when clinicians are selecting an anticoagulant for their patients," said Jack Ansell, MD, lead study investigator and Professor of Medicine at Hofstra-North Shore/LIJ School of Medicine.

"Warfarin's efficacy and affordability have made it the preferred option for millions of patients. Many physicians remain concerned, however, about self-testing relative to issues of management for out-of-range INR results. This unprecedented study shows that weekly self-testing is not only sustainable, but also makes today's warfarin a significantly safer drug," said Gary B. Liska, Global Director, Clinical Development & Education, Alere's Scientific Affairs. "Moreover, better control enhances cost-effectiveness, so these results are especially timely as healthcare cost containment becomes increasingly urgent."

The cost-effectiveness of warfarin versus newer oral anticoagulants for stroke prevention in atrial fibrillation patients was recently examined in five independent studies, in which the threshold of warfarin control needed to be the more cost-effective intervention ranged from 65 percent to 73.5 percent.[3,4,5,6,7] The 74 percent TTR achieved by weekly self-testers in the STABLE study surpassed all of these results.

To watch additional commentary by the lead investigator of the STABLE study, Dr. Jack Ansell, and Gary B. Liska, Global Director of Clinical Development & Education at Alere's Scientific Affairs, please visit http://www.ajmc.com/ajmc-tv/interviews.

About the Study
STABLE is a retrospective analysis of 29,457 patients with diverse indications for warfarin therapy, the most common being atrial fibrillation (72 percent of patients), who had been self-testing for at least six months. Weekly self-testers achieved a mean TTR of 74.0 percent versus 68.9 percent for variable testing frequencies. Among weekly self-testers, patients 65-74 and 75-79 years of age had higher rates of TTR (75.4 and 73.9 percent, respectively) than patients 46-64 years of age (72.4 percent). Weekly testing also was associated with a significantly lower incidence of critical value test results (INR less than 1.5 or greater than 5.0) than was variable frequency testing.  Study results were originally presented at the 2012 annual meeting of the American College of Cardiology.

About Alere
By developing new capabilities in near-patient diagnosis, monitoring and health information technology, Alere enables individuals to take charge of improving their health and quality of life at home. Alere's global leading products and services, as well as its new product development efforts, focus on infectious disease, toxicology, cardiology and diabetes. Alere is headquartered in Waltham, Massachusetts. For more information regarding Alere, please visit www.alere.com.

[1] CMS, 2001.
2 Hylek. NEJM, 1996.

3 Gomez-Outes A, et al. Dabigatran, rivaroxaban, or apixaban versus warfarin in patients with non-valvular atrial fibrillation: a systematic review and meta-analysis of subgroups. Thrombosis. 2013;2013:640723. Epub 2013 Dec 22.

4 Kamel HS, et al. Cost-effectiveness of dabigatran compared with warfarin for stroke prevention in patients with atrial fibrillation and prior stroke or transient ischemic attack. Stroke. 2012;43:881-883.

5 Minno, M. Direct anticoagulant drugs to overcome limitations of vitamin K antagonists. A critical appraisal of data in atrial fibrillation patients. Expert Opinion on Emerging Drugs. 2013;18(1):9-23.

6 You JH, et al. Novel oral anticoagulants versus warfarin therapy at various levels of anticoagulation in atrial fibrillation - a cost-effectiveness analysis. Journal of General Internal Medicine. 2014;29(3):438-446.

7 Shah SV, Gage BF. Cost-effectiveness of dabigatran for stroke prophylaxis in atrial fibrillation. Circulation. 2011;123:2562-2570.


SOURCE Alere Inc.