ZIP code correlates of HIV-testing: a multi-level analysis in Los Angeles.

In this study we examine how individuals' residential areas relate to their HIV-testing, regardless of individuals' characteristics. Data from a 1999 random probability sample of Los Angeles (LA) County adults (n = 5475) was used to conduct a multi-level analysis of HIV-testing among respondents in (1) all 233 ZIP codes and (2) the subset of regions with higher rates of higher-risk sex. Results showed that HIV-testing rates varied across individuals' residential ZIP codes. Throughout LA and in higher-risk regions, residents of areas containing concentrations of African Americans were more likely to test for HIV than residents of White or Latino areas, regardless of individuals' own race/ethnicity or the number of AIDS cases or testing sites in ZIP codes. However, residents of Latino areas were no more likely to test than residents of White areas. This is a concern because of increasing rates of HIV-infection among Latinos. We conclude that opportunities exist to increase testing in Latino higher-risk areas.