Residential segregation and the prevalence of injection drug use among black adult residents of US metropolitan areas

Abstract

Objectives: We analyzed the relationships of two dimensions of racial residential segregation (isolation and concentration) in 1990 to the 1998 prevalence of injection drug use (IDU) among Black adult residents of 93 large US metropolitan statistical areas (MSAs). Methods: We estimated IDU prevalence among Black adults in each MSA by analyzing three databases documenting injectors' encounters with the healthcare system. Multiple linear regression methods were used to investigate the relationships of isolation and concentration to the natural log of Black IDU prevalence, controlling for possible confounders. Results: The median IDU prevalence was 1983/100,000 Black adults (interquartile range: 1422/100,000-2759/100,000). The median isolation index was 0.48 (range: 0.05-0.84): in half of the MSAs studied, the average Black resident inhabited a census tract where ≥48% of the residents were Black. The multiple regression model indicates that an increase of 0.50 in the isolation index was associated with a 23% increase in IDU prevalence among Black adults. Concentration was unrelated to the outcome. Conclusions: Residential isolation is positively related to Black IDU prevalence in MSAs. Research into the pathways linking isolation to IDU is needed. © 2008 Springer Science+Business Media B.V.