This study has identified factors associated with initiation to heroin injecting. The majority of heroin users commenced heroin use via injecting, though those who initiated heroin use via this method had been using heroin for a longer period than those who initiated heroin use via non-parenteral methods. Participants were initiated to injection by a range of people, mainly friends. A large proportion of study participants also reported initiating another person to heroin injection, a practice that was associated with longer heroin use careers and recent sharing of injecting equipment.
