Modeling HIV Risk

Abstract
To provide HIV risk estimates for specific local population subgroups using an HIV risk index combining HIV risk behaviors, prevalence rates, and transmission probabilities. A sample of 270 individuals was studied. Respondents described sexual and injection risk behaviors and partners in the previous 30 days. An HIV risk index was computed for each individual, combining reported sexual and injecting risk behaviors, HIV prevalence estimates for partners and HIV transmission probabilities for each of the risk behaviors. Partner HIV prevalence rates were estimated from a national sample, and HIV transmission probabilities were obtained from previously published studies. Projected risk estimates were found to differ a great deal within major demographic categories. Highest 10-year risk was found among African-American male gay injectors (72%) and the lowest among white male heterosexual noninjectors (<.01%). The method used here for estimating HIV risk can be calculated for specific at-risk population subgroups of any size and composition, including individuals. By understanding which specific subpopulations are at risk, specific interventions and public health campaigns may be better targeted.