Dr. Mary Vaughan-Sarrazin, Associate Professor of General Internal Medicine, has been awarded a three-year, $950,000 grant from the National Institutes of Health to evaluate the use of four FDA-approved anticoagulants for stroke prevention in individuals with atrial fibrillation (AF). Since 2010, dabigatran, rivaroxaban, apixaban, and edoxoban, which are collectively known as non-vitamin K oral anticoagulants (NOACs), have been approved for use in two doses for patients with non-valvular AF. For most people, the standard dose is appropriate, and lower doses have also been approved for specific subsets of people, such as those with impaired renal function. However, there is growing evidence that many patients do not receive the appropriate NOAC dose, which may lead to inadequate stroke prevention (if patients are under-dosed), or increased risk of dangerous bleeding (if patients are over-dosed). 

Dr. Vaughan-Sarrazin and her team will examine the extent to which FDA-approved dosing recommendations for NOACs are followed in a large cohort of elderly patients with AF. Additional aims are to evaluate differences in outcomes—death, stroke, or major bleeding events—among patients who were under, over, or adequately coagulated with a NOAC, estimate the potential number of strokes or bleeding events the might have been prevented (or incurred) if FDA-recommended dosing guidelines were followed, and explore other patient characteristics that may be relevant factors to consider when dosing NOACs. The study will use clinical and administrative data of individuals enrolled in Medicare managed care through Humana, Inc. Dr. Vaughan-Sarrazin is a Director of Data Analysis Cores for Iowa City VA Center for Access and Delivery Research and Evaluation (CADRE), VA Midwest Rural Health Resource Center, and the VISN 23 Patient Aligned Care Teams (PACT) Evaluation Laboratory.