Project Summary
PCORI has identified long-term use of blood thinner 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 thinner 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.
COVID-19-Related Project EnhancementCOVID-19 appears to be associated with abnormal coagulation and may increase the risk of venous thromboembolism (VTE) and other thrombotic events. A better understanding of the broad prevalence of post-hospitalization VTE and the risk of VTE in key subgroups is of great interest to patients and clinicians. The research team will conduct an observational study that aims to answer questions about the risk of COVID-19-related VTE broadly and in key patient subgroups, including older adults, those with a prior history of VTE, and those with severe COVID-19. Enhancement Award Amount: $500,000 |
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?
Each year, more than 500,000 people in the United States are hospitalized because of blood clots that form in their veins. Most blood clots form in people’s legs. But the clots can break loose and travel to the lungs, causing serious problems including death. More than 100,000 people in the United States die each year from blood clots that travel to their lungs.
For people who have had blood clots, blood thinners can prevent future blood clots. These medicines work well to prevent clots, but they may cause complications such as severe or uncontrolled bleeding.
Researchers don’t know whether some blood thinners work better than others to prevent future blood clots. They also don’t know whether some blood thinners are less likely than others to cause bleeding problems in people who take them for longer than three months. Few studies have looked at the use of blood thinners in people who are older, have kidney disease, or have had bleeding complications.
This study is looking at the benefits and risks of five blood thinners. The research team is comparing people who take these medicines for only three months with people who take these medicines for more than three months. The study is also comparing a blood thinner that has been available for a long time (warfarin) with four newer medicines: dabigatran, rivaroxaban, apixaban, and edoxaban. The research team is comparing the benefits and risks of the medicines for people with different characteristics.
Who can this research help?
This research can help people who need to take a blood thinner for more than three months. They and their doctors can use information from this study to help choose a medicine.
What is the research team doing?
The research team is looking at electronic health records for adults treated for a blood clot between 2010 and 2018 at Kaiser Permanente facilities in California. The patients have already taken blood-thinning medicine for at least three months. The research team is collecting information about patients’ health backgrounds, prescribed blood thinners, and changes in health. The team is asking people treated for a blood clot between 2015 and 2018 to take a survey. Questions ask about their health, well-being, and satisfaction with the treatment they received.
The researchers are looking at the number of blood clots each treatment prevented. They also are looking at the number of bleeding complications each treatment caused. The team is examining whether the risks and benefits differ for people with different characteristics, such as being older, having kidney disease, or having a high risk of bleeding. Patients who have had blood clots helped design the study and the survey.
Research methods at a glance
| Design Element | Description |
|---|---|
| Design | Observational: cohort study |
| Population | Adults who have had a blood clot and completed at least 3 months of treatment with blood thinners |
| Interventions/ Comparators |
|
| Outcomes | Number of blood clots, number of bleeding complications |
 |
Up to 10-year follow-up for study outcomes |
Project Details
Older Adults
New Oral Anticoagulants (NOACs) in the Extended Treatment of Venous Thromboembolic Disease