Walk score and risk of stroke and stroke subtypes among town residents

Background—Regular physical activity, including light-to-moderate activity, such as walking, has wellestablished benefits for reducing the risk of ischemic stroke. It remains unknown, however, whether the characteristics of cities themselves can influence the risk of stroke by promoting such activity. Objectives—We tested the hypothesis that how walkable a city will be associated with the risk of ischemic stroke in persons residing in that city. Methods—We calculated the age-adjusted annual incidence rates of ischemic stroke among residents in each of the 63 cities in Minnesota for which Walk Scores were available using 2011 Minnesota Hospital Association (MHA) data. Walk Score®, an online service, uses an exclusive algorithm to compute a walkability score between 0 and 100 for any location within the United States. The score is calculated based on the distance to amenities in nine categories (grocery, restaurants, shopping, coffee, banks, parks, schools, books, and entertainment) weighed according to their importance. Results—There are 2,910,435 persons residing in the 63 Minnesota cities in our data (average population per town is 46,197). The average Walk Score of the 63 towns in Minnesota was 34, ranging from 14 to 69. The average median age of residents was similar in tertiles of towns based on Walk Score as follows: ≤25 (n=9) 36 years; 26–50 (n=46) 37 years; and 51–100 (n=8) 35 years. The age-adjusted incidence of ischemic stroke was similar in tertiles of towns based on Walk Score as follows: ≤25 (n=9) 341 per 100,000; 26–50 (n=46) 308 per 100,000; and 51–100 (n=8) 330 per 100,000 residents. The correlation between age-adjusted ischemic stroke incidence and Walk Score was low (R 2=0.09) within Minnesota. Conclusions—The ready availability of indices such as Walk Score make them attractive options for ischemic stroke risk correlation. Despite the lack of relationship in our study, further studies are required to measure the magnitude and health benefits of light-to-moderate activities performed within a town.