Travel distance to outpatient substance use disorder treatment facilities for Spanish-speaking clients

Travel distance and English proficiency skills are widely recognized factors associated with service access and treatment engagement. As Latino populations represent one of the most rapidly growing populations in the United States, methods are needed to better understand availability of linguistically appropriate services in Latino communities. Given regional variability in the density of Latino communities, the current study examines treatment access as travel distance to outpatient substance use disorder treatment facilities in one of the largest and most rapidly changing Latino communities in the United States - Los Angeles County, CA.

Data from the 2010 U.S. Census and the National Survey of Substance Abuse Treatment Services were analyzed using a geographic information system approach to determine the street-level distance between treatment facilities with services in Spanish and Latino communities throughout L.A. County. This study used an innovative approach that included network analysis and spatial autocorrelation to identify "hot spots," i.e. clusters of census tracts with high-density Latino populations that were relatively far from treatment services in Spanish.

The analysis identified several key hot spots with significantly large Latino populations and far street distances to the closest facility offering Spanish-language services. The average distance between these hot spots and the closest facilities was 2.74 miles (SD=0.38), compared to a county average of 2.28 miles (SD=2.60). In several key hot spots, the distance was greater than 3 miles.

Despite the growing presence of Latinos in L.A. County in 2010, constrained access to services in Spanish was found in geographic locations highly represented by Latinos. The distances identified in this study are almost triple the 1-mile threshold representing reduced access to treatment as determined by other studies. Geographic information systems represent an innovative and user-friendly approach for effectively and efficiently identifying areas with the greatest service needs. This approach can inform policies to increase the capacity of ethnic minority communities to develop linguistically responsive social services.