Analysis of Canadian population with potential geographic access to intravenous thrombolysis for acute ischemic stroke.

Abstract

We sought to identify the Canadian population with potential access to intravenous tissue plasminogen activator within 3 hours of onset of acute ischemic stroke. Assuming that 60 minutes is needed for stroke recognition, emergency room evaluation, and administration of tissue plasminogen activator, 120 minutes remain for transport, using a 3-hour treatment window. Ambulance databases were analyzed for transport times of 60, 90, and 120 minutes and were found to correspond to transport distances of 32, 64, and 105 kilometers (20, 40, and 65 miles), respectively. Using Geographical Information System (GIS) software, these radii were overlaid on thematic maps of Canadian hospitals identified as having a third- or fourth-generation CT and with a neurologist and an emergency physician on staff. Analysis was then performed on complete Canadian census data from 1991 and the interim 1996 census count. 67.3%, 78.2%, and 85.3% of the total Canadian population were within 32, 64, and 105 kilometers, respectively, of an identified hospital. For individuals >/=65 years of age, 64.4%, 77.0%, and 85.7% were within the respective radii. Complete analysis by age, ethnic origin, and gender are detailed. In the model described, a substantial percentage of the Canadian population has geographic access to a hospital potentially capable of delivering intravenous thrombolysis for acute ischemic stroke. GIS analysis can identify both population groups and rural areas with limited access to thrombolytic stroke treatment. A coordinated emergency medical service response for stroke is advocated to maximize coverage, as a 60-minute delay in emergency room arrival eliminated 5.1 million people from potential treatment.