Expansion of Hospital Stroke Care Capacity: A Multi-Level Analysis on Access to Care, Treatment, and Outcomes - Although advances in the treatment of stroke have significantly decreased morbidity and mortality for stroke patients in the United States, there has been variation in the distributional outcomes of the provision of stroke services across Black and White, low-income, and rural patients. No studies have examined these changes in stroke care capacity across communities and how it has affected these patients. The long-term goal of this project is to identify pathways in the delivery of acute stroke care that contribute to differences in care for Black, Hispanic, low-income, and rural patients. The overall objective is to determine the mechanisms through which patients experience variation in stroke care. Using national data from 2009 to 2019, we propose three aims to test the following hypotheses: Aim 1, That there is differential adoption of levels of stroke care across communities, resulting in increased differences in geographic access to care. Aim 2, That patients in communities with lower socioeconomic indicators (such as low-income, low home ownership, lower education attainment) experience increased differences in admission to stroke centers and treatment due to patient redistribution across hospitals with different levels of stroke care and differential treatment within hospitals. Aim 3, That there are widening differences in health and functional outcomes across community types, and between Black, Hispanic, and low-income patients compared with their counterparts within the same communities. In Aim 1, we will identify if there is a differential adoption rate of stroke care centers across different types of communities. These results will aid certification bodies to consider incorporating community need in certification guidelines. In Aim 2, our results will illuminate patient redistribution patterns in communities that gain access to stroke care and pinpoint patients who experience differences in admission to stroke centers and treatment. Results will identify the types of communities where outreach might be most effective in reducing heterogeneity in stroke care. In Aim 3, our results will determine how differences among stroke patients: a) changed across community types after adoption of stroke care, compared to communities with no change; and b) between Black, Hispanic, low-income, and rural patients within the same community when those communities experience changes in stroke care, relative to those in communities with no change in access to stroke care. These findings will identify specific communities where additional interventions (e.g., mobile stroke units, enhancing telehealth access) could yield the greatest benefits.