Figure Caption: Spatial Accessibility to Pharmacies in Baton Rouge by Different Travel Time Catchment Area Sizes.
This study examines spatial accessibility of pharmacies in Baton Rouge, Louisiana. Two popular geographic information systems (GIS)-based methods are compared: the proximity method uses the distance (travel time) from the nearest pharmacy, and the two-step floating catchment area (2SFCA) method considers the match ratio between providers and population as well as the complex spatial interaction between them. The study indicates that disproportionally higher percentages of African-Americans are in areas with shorter travel time to the nearest pharmacies than whites, but suffer from poorer accessibility measured by the 2SFCA method-that is, fewer pharmacies per 10,000 residents. Seniors, particularly those of seventy-five years or older, tend to be disproportionally concentrated in areas that not only are closer to pharmacies, but also have more pharmacies per 10,000 residents. The two methods used in the study capture different elements in spatial accessibility: one being physically close to a facility and another adding the crowdedness in service. Both properties can be valuable for residents. The two may not always coincide with each other in spatial variability, as it is the case for racial disparity in our study area. However, when they do, as in the case for seniors, it may imply a true (dis)advantage for a demographic group in terms of both properties of spatial accessibility.