This study explores the spatial accessibility of outpatient drug treatment facilities and the potential relationship with drug use-related outcomes among Mexican American heroin users. Secondary data on 219 current and former heroin-injecting Mexican American men aged 45 and older were drawn from a research study in Houston, Texas. We used geographic information systems (GIS) to derive two spatial accessibility measures: distance from one's place of residence to the closest drug treatment facility (in minutes); and the number of facilities within a 10-minute driving distance from one's place of residence. Exploratory logistic regression analyses examined the association between the spatial accessibility of drug treatment facilities and several drug use-related outcomes: internal locus of control (LOC); perceived chances and worries of injecting in the next six months; treatment utilization; and location of last heroin purchase.
Participants with greater spatial access to treatment programs were more likely to report a higher chance of injecting in the near future. However, while current heroin users were more worried about injecting in the next six months, greater spatial access to treatment programs seemed to have a buffering effect. Finally, those who lived closer to a treatment programs were more likely to have last purchased heroin inside the neighborhood versus outside the neighborhood. Spatial accessibility was not associated with internal LOC or treatment utilization.The findings showed that the presence of outpatient treatment facilities—particularly services in Spanish—may influence perceived risk of future heroin use and purchasing behaviors among Mexican American men. Implications for future spatially-informed drug use research and the planning of culturally and linguistically responsive drug treatment programs are discussed.