Multilevel analysis of HIV related risk behaviors among heroin users in a low prevalence community

BACKGROUND: Injecting drug users (IDU) are at increased risk of human immunodeficiency virus (HIV) infection. Their HIV prevalence however varies from place to place and may not be directly linked with the level of individual risk. This study explores the relative importance of individual and community level characteristics in the practice of HIV-related risk behaviors in IDU in Hong Kong where the HIV prevalence has remained low at below 1%. METHODS: Methadone clinics were used as the channel for accessing drug users in Hong Kong. HIV-related risk factors in drug users attending these clinics were retrieved from a questionnaire routinely administered to newly admitted and readmitted clients, and assessed using logistic regression and multilevel analyses. RESULTS: Between 1999 and 2005, a total of 41196 person-admissions were recorded by 20 methadone clinics. Male gender, older age and new admissions in bigger clinics located in districts with older median age were more likely to have engaged in HIV related risk behaviors including heroin injection, needle sharing, unprotected sex and having multiple sex partners (p < 0.05). CONCLUSION: Multilevel analysis is a useful adjunct for determining the association between risk behaviors and both individual and community factors in IDUs, which can be demonstrated even in low HIV prevalence settings.