Bridging Disciplinary Boundaries (January 11 - 14, 2007)


Using Geographic Information Systems to Examine Health Access for Immigrant Communities in Los Angeles County

Dennis T. Kao, MSW, University of Southern California.

PURPOSE: This study utilizes Geographic Information Systems (GIS) to examine the issue of health access for immigrant communities in Los Angeles County. Immigration can drastically alter local constituencies, especially in large urban areas, such as Los Angeles County that tend to attract large numbers of immigrants. Both the magnitude and rate of this growth translates to tremendous challenges for the local health delivery system. Among the array of health access barriers immigrants face, spatial accessibility – which refers to the geographic availability and accessibility of local health services – has been shown to be an important factor in either impeding or facilitating the capacity of individuals to access health services. To date, very little research has focused on the issue of spatial accessibility as it applies to immigrant populations or communities. METHODS: This analysis utilized GIS software and spatial analytical methods to derive a series of map layers that can be then compared to assess for the existence of significant spatial patterns. Kernel density methods were conducted to create a spatial accessibility map layer, which reflects the average health facility-to-population ratio in each census tract. Local spatial autocorrelation statistics were used to identify groupings of census tracts with similarly high and low concentrations of immigrants, i.e. “hot” and “cold” spots (at significance levels of p < .05). The resulting map layers were then overlaid with one another and visually assessed. RESULTS: Examination of the derived map layers suggest that high-immigrant communities tend to more concentrated in areas with lower levels of spatial accessibility, compared to low-immigrant communities. There, however, appears to be some regional variation, with slightly different spatial patterns occurring in the western region versus the eastern region of the county. With the exception of the Central/East Los Angeles area, communities with the highest concentration of immigrants are located in areas with medium-low to low levels of spatial accessibility. The high levels in the Central/East LA area might be attributed to its location in one of the county's primary “urban centers.” IMPLICATIONS: Given the important role that ethnic clustering plays in the residential patterns of immigrants, more focus on these geographic dimensions of health access can potentially lead to a better understanding of the health utilization patterns in immigrant or other ethnic communities. This type of analysis can prove to be helpful for policymakers, administrators, and providers in the ongoing effort to make quality health care accessible to an ever-changing population. The findings in this study suggest that geography does, in fact, matter and that the location of health facilities – without a long-term strategy that considers population change – can disproportionately affect certain groups or communities. More broadly, this study attempts to show that GIS can be a powerful tool that allows policymakers, planners, and social workers to identify gaps in the current service delivery system and therefore, can greatly facilitate the planning process. However, despite advances in technology and the proliferation of more user-friendly software, GIS remains seriously underutilized in social work research and practice.