Access to Safety Net Health Services Providers: Los Angeles County

Publication Date


Committee Chair

Mark P. Kumler, Ph.D.

Committee Members

Bradley Jamison, Ph.D.
Karen K. Kemp, Ph.D.


Minority populations bear the burden of a disproportiionately high rate of illness and premature death in the United States. Current research addressed by the Agency for Healthcare Research and Quality suggests low levels of health insurance, low levels of income and education, inequitable diagnoses and treatments, and cultural and communication barriers as the explanations for most health care disparities. This project has been designed to investigate the possibility of a spatial component to health care disparities.

More than 53,000 people in Los Angeles County live further than thirty minutes away from the nearest safety net health service provider. Safety net service providers provide a variety of primary care services to low income and vulnerable populations. This project subdivided the population by race/ethnicity and socioeconomic characteristics. For each group a weighted census tract centroid was calculated based on census block data for race/ethnicity or based on census block group data for socioeconomic characteristics. Census tract centroids were chosen for the purpose of maintaining consistency between all groups, while also maintaining a manageable quantity of points for processing within a personal geodatabase.

Network Analyst for ArcGIS 9.1 was used to calculate network distances between the weighted population centroids and the nearest safety net health service provider. A travel time index calculated by the Texas Transportation Institute was used to adjust for peack hour traffic conditions. Differences between the groups were examined for statistical significance with a two-sample t-test between proportions. Only the proportions traveling further than thirty minutes were tested. Thirty-eight of the t-tests between proportions found significant differences in the percentages traveling further than thirty minutes. With the exception of Native Americans, minority populations are the most well served and are traveling significantly shorter distances than non-Hispanic whites in Los Angeles County.

Full text is available at the University of Redlands


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