INTRODUCTION: Opioid agonist treatment (OAT) is one of the most effective treatments for opioid dependence, but there can be barriers to accessing treatment. This study examined characteristics associated with OAT engagement-never, previous or current-among people with opioid dependence in NSW, Australia, following recent reforms to OAT access.

METHODS: Between October 2023 and March 2024, people with opioid dependence were recruited from services and community settings across NSW. Participants completed structured interviews on socio-demographics, mental health disorders, substance use and use of prevention and treatment services. Logistic regression was used to examine associations between participant characteristics and engagement with OAT.

RESULTS: Of 403 participants (mean age 44; 65% male), 77% were currently receiving OAT (60% methadone, 11% sublingual buprenorphine and 27% long-acting injectable buprenorphine), 13% previously and 9% never. Differences between OAT status groups included those currently receiving OAT reporting lower rates of homelessness and extra-medical opioid use, and greater group therapy engagement and past-year receipt of naloxone kits compared to those previously and never receiving OAT. Past-month daily injecting drug use was higher among those previously and never receiving OAT; those previously receiving OAT also reported the highest rate of past-year supervised injecting facility use and overdoses in the past 6 months.

DISCUSSION AND CONCLUSIONS: Those not receiving OAT reported greater social instability, recent injecting drug use and drug-related harm. Variation in harm reduction service use suggests tailored strategies are needed to reach those outside OAT. These findings highlight the need for integrated, diverse strategies to address dependence-related harms.