A cross-national analysis of the effects of methadone maintenance and needle and syringe program implementation on incidence rates of HIV in Europe from 1995 to 2011

Although many studies have found an association between harm reduction interventions and reductions in incidence rates of Human Immunodeficiency Virus (HIV) infection, scant research explores the effects of harm reduction cross-nationally. This study used a year- and country-level fixed effects model to estimate the potential effects of needle-and-syringe programs (NSPs) and methadone maintenance therapy (MMT) on incidence rates of HIV in the general population and among people who inject drugs (PWID), in a sample of 28 European nations. After adjusting for Gross Domestic Product (GDP) and total expenditures on healthcare, we identified significant associations between years of MMT and NSP implementation and lower incidence rates of HIV among PWID and the general population. In addition to years of implementation of NSP and MMT, the greater proportion of GDP spent on healthcare was associated with a decrease in logged incidence rates of HIV. The findings of this study suggest that MMT and NSP may reduce incidence rates of HIV among PWID cross-nationally. The current study opens a new avenue of exploration, which allows for a focus on countrywide policies and economic drivers of the epidemic. Moreover, it highlights the immense importance of the adoption of harm reduction programs as empirically-based health policy as well as the direct benefits that are accrued from public spending on healthcare on incidence rates of HIV within the general population and among subpopulations of PWID.