Association of smoking with HIV and drug risk behaviors in injection drug users in Baltimore, Maryland

BACKGROUND: Tobacco use is the largest preventable cause of death in the U.S. and HIV-positive individuals have a high prevalence of cigarette smoking. METHODS: Associations between cigarette smoking and drug risk behaviors were examined using data from 669 injection drug-users (IDU) in the 2005 wave of the National HIV Behavioral Surveillance System in Baltimore, Maryland, a cross-sectional survey using respondent-driven sampling. Analyses were conducted in Stata using individual sampling weights generated by the Respondent-Driven Sampling Analysis Tool (RDSAT). Multivariate Poisson regression with robust variance estimation was used to identify factors associated with heavy vs. light smoking. RESULTS: The adjusted prevalence of no smoking, light smoking (<1 pack/day), and heavy smoking (≥1 pack/day) in this IDU population were 8.0%, 32.7%, and 59.3%, respectively. HIV prevalence was higher among smokers compared to non-smokers (p = 0.001) and bivariate analyses showed that heavy smokers were less likely to report being HIV positive (p = 0.016) or to have seen a doctor in the past year (p = 0.004) than light smokers. In multivariate analyses adjusted for demographics, heavy smokers were significantly less likely to be African American and have a high school education; they were more likely to have been arrested, binged on alcohol and used crack, oxycontin, or non-injected heroin in the past year. CONCLUSIONS: Knowledge of smoking history may provide insight into the spectrum of addiction and other HIV risk behaviors among IDU. Integrating smoking cessation with HIV prevention and harm reduction services could address unmet health needs in Baltimore IDU.