Abstract TMP41: Mapping Accessibility Differences of Acute Stroke Centers in the United States

Abstract

Background: One of the keys to mitigating adverse outcomes of an ischemic or hemorrhagic stroke is timely access to a stroke center. Every minute of a large vessel occlusion results in the mean loss rate of 2 million neurons. Every 20-minute reduction in time to reperfusion increases disability-free lifespan by 3 months. For intracerebral hemorrhage, early intensive blood pressure lowering within 2 hours of onset improved outcomes . For aneurysmal subarachnoid hemorrhage, more than one-third of rebleeds occur within 3 hours. Accessibility of acute stroke centers varies drastically across the United States, both between states and between localities. There is a need to characterize accessibility not only based on the population and distance to the nearest center but also using average travel time per area. Methods: To understand the accessibility of the 2,446 stroke centers in the US we performed geospatial mapping by combining distance and average travel time as part of an interactive map. The map can be used to visually identify regions lacking timely access to a stroke center. Through linking highly granular demographic and socio-economic census data, we can better understand populations effected by long travel times. To identify the nearest stroke center for every census tract in the US, the distance between centroids and the KNN algorithm was used. By adding the average commute times of the counties that intersected the straight line, travel time to the nearest stroke center was estimated. Results: Approximately 45 million people live over 90 minutes away from a stroke center. Increasing stroke center access should be prioritized for populations over 1.5 hours from the nearest stroke center. The map highlights regions of particular concern with 2.5 - 4+ hour travel times (Fig. 1). Conclusion: We demonstrate that accessibility differences of stroke centers can be better understood using an interactive map. Our map highlights regions and populations in need of a stroke center.