Integrating Spatial and Aspatial Factors in Measuring Accessibility to Primary Health Care Physicians: A Case Study of Aboriginal Population in Sudbury, Canada

Heath care accessibility can be determined in both a spatial and aspatial context. While spatial access is the geographic restraints limiting one’s ability to access care, apatial access refers to the non-geographic constraints affecting access to care, typically measured by socio-economic factors. The paper presents a methodological framework to combine spatial and aspatial factors to assess the accessibility to primary care physicians. Attention is focused on the aboriginal population within an isolated city, Sudbury, in northern Ontario, Canada. A range of datasets were analyzed including the 2008 Canadian Medical Directory, 2006 census and 2008 DMTI road network data. Spatial accessibility of the aboriginal population to family physicians was measured using the enhanced two-step floating catchment area model that accounts for varying travel time thresholds associated with different travel time zones. The z-score-based aspatial scores were calculated at a DA level to reveal the highest and lowest concentrations of the aboriginal population in the study area. Combining the spatial and aspatial scores allows for problem census DAs to be determined where there are both low spatial scores and a high concentration of the aboriginal population. The methodology developed in this paper is flexible with the ability to be altered to fit different studies in different geographic regions. It provides results that are easy to interpret by health policy makers.