Homelessness and HIV risk factors associated with injection drug use in Houston, Texas, 2009

Background: The prevalence of HIV is higher among the homeless compared to non-homeless populations. This analysis examines homelessness as a factor affecting HIV risk behaviors associated with injection drug use. Methods: Our study includes 523 eligible injection drug users (IDUs), recruited into the 2009 cycle of the National HIV Behavioral Risk Surveillance project. Three separate multivariable logistic regression models were used to identify the association of homelessness with: 1) always using a new sterile needle; 2) sharing needles; and 3) sharing drug-preparation equipment. All three models were adjusted for potential confounders selected through univariate analyses using a cut point of p<0.1. Results: 251 (48%) of our sample population of IDUs reported being currently homeless. In all three models, homelessness was associated with risky injection behavior: homeless IDUs had lower odds of always using a new sterile needle (OR=0.57, 95% CI: 0.37-0.87) and greater odds of sharing needles (OR=2.21, 95% CI: 1.50-3.25) and of sharing drug-preparation equipment (OR=1.74, 95% CI: 1.13-2.66). In addition to homelessness, being arrested in the past 12 months (OR=1.52, 95% CI: 1.04-2.22) was associated only with sharing needles but not with using a new sterile needle or sharing equipment. Discussion: Our results show that structural/environmental factor such as homelessness, are associated with individual risk behaviors, like needle sharing. The findings underscore how important it is to considering structural/environmental factors with individual risk factors when designing interventions to reduce HIV risk. Interventions targeting system-level change may help to reduce the burden of HIV among the homeless injection drug user population.