Project Summary/Abstract Anticoagulants are used for indications ranging from stroke prevention in atrial fibrillation to the acute treatment of venous thromboembolism. However, anticoagulants are also associated with significant risks of bleeding, as well as costs and burden to patients. Despite the morbidity and mortality associated with cerebrovascular diseases and stroke, many people do not receive antithrombotic therapy, and many people at high embolism risk are not anticoagulated. Dementia and cognitive decline are commonly cited as deterrents to anticoagulant use. This administrative supplement has two major goals (1) to create research infrastructure to support junior investigators studying the intersection between thrombosis, anticoagulant medications, and dementia; and (2) to expand Dr. Margaret Fang's research program in thrombosis to examine the association between atrial fibrillation, antithrombotic medications, and cognition. Funding from this supplement will be used to refine and characterize dementia outcomes in a sub-cohort of people with atrial fibrillation in the longitudinal Health and Retirement Study. Dr. Fang is a hospitalist and the Research Director of the University of California, San Francisco (UCSF) Division of Hospital Medicine. Her research program is based in the outstanding clinical, training, and research environment of UCSF and connects investigators in hospital medicine, hematology, geriatrics, and pharmacology.