PCORI has identified long-term use of blood-thinning medicines as an important research topic. Blood thinners help prevent blood clots, but these medicines may cause other health problems if taken for a long time. Patients, clinicians, and others want to learn: How do different long-term blood-thinning treatments compare for patients who have had a blood clot? To help answer this question, PCORI launched a funding initiative in 2015 on New Oral Anticoagulants (NOACs) in the Extended Treatment of Venous Thromboembolic Disease. This research project is one of the studies PCORI awarded as part of this program.
This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.
What is the research about?
More than 500,000 people in the United States are hospitalized each year because of blood clots that form in their blood vessels. Most blood clots form in people’s legs, but the clots can break loose and go into the lungs, causing serious problems, including death. On average, one in five people dies within one month of being diagnosed with a blood clot in the legs or lungs.
Some people who have had a blood clot in their legs or lungs need to take medicines called blood thinners for a long time to prevent additional clots. These medicines work well to treat blood clots and prevent new ones. But the medicines may have side effects, such as severe or uncontrolled bleeding. Treatment guidelines do not specify which blood thinners to use for long-term treatment of blood clots. Some blood thinners may work better than others to prevent additional clots or may be less likely to cause bleeding problems. In addition, research studies have not answered which blood thinner achieves the best balance between benefits and harms when taken for the long term.
This study compares the benefits and risks of all five available blood thinners when people take these medicines for the long term.
Who can this research help?
Information from this study can help people who have had a blood clot—and their doctors—choose a treatment.
What is the research team doing?
The research team is comparing the benefits and harms of five different blood thinners that people use for extended periods to prevent blood clots. The team is
- Comparing the benefits and harms of each medicine
- Looking at how the treatments work in different groups of people
- Comparing their study results with findings from similar research
Patients who use these blood thinners, and also doctors, are working with the research team to design, conduct, and interpret the study.
The research team is using information from electronic healthcare databases that contain information about diagnoses, procedures, and prescribed drugs for more than 215 million people in the United States. The team is including people who used blood thinners for at least three months after having a blood clot, and continue to use them for longer. The study does not include people who used blood thinners before having a blood clot. The study is paying particular attention to how the blood thinners work for older adults, people with kidney impairment, and people who are at high risk of bleeding.
The study is comparing the benefits and harms of different blood thinners by examining how many people taking each medicine have blood clots or bleeding complications at any time for up to 10 years after being diagnosed with a blood clot. The team is also looking at how many people die from any cause after long-term treatment with the five medicines being studied.