The Research Outcome Study in Ireland (ROSIE) is the first national, prospective, longitudinal, multi-site drug treatment outcome study in the country. The National Advisory Committee on Drugs (NACD) commissioned this research in 2002 as required by the National Drugs Strategy Action 99. The aim of the study was to recruit and follow opiate users entering treatment over a period of time, documenting the changes observed.

The study recruited 404 opiate users entering treatment. Outcomes at 3-years for drug use, involvement in crime, injecting-related behaviour, physical and mental health, among others, are presented in this paper. Statistically significant differences are given emphasis in this document.