Twelve-month outcomes for heroin dependence treatments: does route of administration matter?

A sample of 442 heroin users (394 injecting heroin users: IHU, 48 non-injecting heroin users: NIHU) recruited for the Australian Treatment Outcome Study were reinterviewed at 12 months after entrance to treatment for heroin dependence. Route of administration was stable over the follow-up period with 4% of NIHU having made a transition to heroin injecting, and 0.3% of IHU having made a transition to non-injecting. Given the clinical profile of NIHU presented in the literature, it might be expected that they would exhibit better treatment retention and 12-month outcomes than IHU. At 12 months, however, there were no differences between NIHU and IHU in heroin use, heroin dependence symptoms, polydrug use, criminality, current self-reported physical health or psychopathology. The only group differences at 12 months were that NIHU were more likely to be employed and had fewer injection-related problems. It is concluded that, among those presenting for treatment, route of administration is not an indicator of likely outcome.