Katharine E. Poundstone, MHS, Byron Crape, MSPH, Upinder K. Jodhka, Joseph C. Bareta, MS, Steffanie A. Strathdee, PhD, and David D. Celentano, ScD. Department of Epidemiology, Infectious Disease Program, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, Baltimore, MD 21205, 410-955-1356, kpoundst@jhsph.edu

Background: Concentrated disadvantage and physical housing characteristics at the neighborhood level have been associated with a variety of health outcomes. This study examined the relationship between neighborhood characteristics and HIV seroconversion among a cohort of injection drug users (IDUs) in Baltimore, Maryland.

Methods: Since 1988, IDUs participating in a longitudinal study of HIV seroconversion underwent semi-annual HIV tests and interviewer-administered surveys. Participants°¦ residences at enrollment were geocoded and assigned to 1990 Census block groups, whereby neighborhoods were defined. Neighborhood exposures were constructed using 1990 Census data, including measures of income, education, poverty, residential stability, and physical housing characteristics. Univariate and logistic regression analyses were performed to assess ecological associations between block group level characteristics and HIV seroconversion.

Results: Of 1559 initially HIV-negative IDUs, 72.6% were male, 92.3% were African American and median age was 36; 312 IDUs serconverted by 2002 (HIV incidence density: 2.51 per 100 person years). In univariate analyses, high levels of owner-occupied housing and high median rent were negatively associated with HIV seroconversion (c²=9.11 and c²=9.76, respectively, p<0.05), while measures of income, education, poverty, and physical housing characteristics were not significantly associated with HIV seroconversion. In stepwise multiple logistic regression analysis, higher median rent at the block group level was significantly protective [OR 0.83 (95% CI: 0.73, 0.94)].

Conclusion: These preliminary ecological results suggest that key block group characteristics may be useful indicators of neighborhood level HIV risk. Neighborhood characteristics may play a key role in multilevel pathways linking the social environment, individual behaviors, and HIV risk.

Learning Objectives:

• 1. Describe 3 key features of the neighborhood social environment that may be related to HIV risk;
• 2. Identify 5 measurable variables that can be used to model the effects of the neighborhood environment on HIV risk;
• 3. Articulate an approach to mapping and investigating relationships between neighborhood and community level characteristics and individual health outcomes

Keywords: HIV/AIDS, Community Health

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.