Abstract T P187: Regionalization of Endovascular Therapy for Acute Ischemic Stroke in California, 2009-2010

Abstract

Background: The regional availability of hospitals with expertise in applying endovascular therapy for acute ischemic stroke is critical to ongoing efforts to develop effective interventions for this time-sensitive indication. We sought to assess the geographic proximity of stroke patients in California to centers that perform endovascular stroke therapy. Methods: We identified all hospitalizations for ischemic stroke at all 366 non-federal acute care hospitals in California from 2009 to 2010, including the subset where endovascular stroke therapy was employed, using data from the Office of Statewide Health Planning and Development. ZIP code centroids were used to estimate the geographic distance between a treating hospital and the patient’s residence. Using these distances, we estimated the proportion of stroke patients that lived within 2-hour (65 mile) transport distance to a hospital that performed certain threshold volumes of endovascular stroke cases each year. Results: From 2009-10, endovascular stroke treatment was used in 643 of 104,350 (0.6%) hospital discharges for ischemic stroke in California. A majority (60%) of these procedures were performed at hospitals that performed at least 12 procedures per year, and 83% of these procedures were performed at hospitals that performed at least 6 procedures per year. Of the 366 hospitals, 54 (15%) performed at least one endovascular stroke procedure per year. The median number of procedures per hospital per year was 3.5 (IQR 1-9). In-hospital mortality for endovascular stroke therapy was 21%, and a higher procedural volume at the hospital level was not associated with lower mortality. Most (86%) stroke patients lived within 65 miles of a center that performed at least 6 procedures per year (median with IQR, 9.5[7-17]), and 97% were within 65 miles of a center that performed at least 1 procedure per year. Conclusion: In 2009-10, less than 1% of ischemic stroke hospitalizations in California involved the use of endovascular stroke therapy. Most patients lived within a 2-hour transport distance from a center that performed at least one endovascular procedure per year.