Understanding injecting drug use in contemporary Australian settings
thesisposted on 27.02.2017, 23:16 by Horyniak, Danielle Rebekah
Injecting drug use is an important public health issue, causing significant morbidity and mortality worldwide. The contemporary drug market setting in Australia is defined by a lower prevalence and frequency of heroin injection among regular people who inject drugs (PWID) compared with in the past, and changing patterns of polydrug use, with some evidence of increasing use of pharmaceutical opioids. Our understanding of patterns of drug use and related risk behaviours among contemporary PWID is limited by the fact that much research has captured samples of predominantly older, long-term PWID, many of whom are on opioid substitution therapy (OST) and may use drugs only infrequently. The aim of the research presented in this thesis was to generate comprehensive information about patterns of drug use and associated risk behaviours among PWID who are active in contemporary settings, including understudied populations such as younger PWID, out-of-treatment PWID and PWID from culturally and linguistically diverse backgrounds. The Melbourne Injecting Drug User Cohort Study (MIX) is a prospective cohort of 688 community-recruited regular PWID. The median age of the cohort is 27.6 years and only 35% of participants were prescribed OST at baseline. Over 70% of the cohort completed a follow-up interview at 12 months post-baseline, demonstrating that it is possible to successfully retain a cohort of community-recruited PWID. Despite the uniqueness of this cohort, patterns of drug use by MIX participants were relatively similar to those displayed by sentinel samples of older, longer-term PWID. There were few differences in injecting initiation experiences between MIX participants who initiated injecting in contemporary settings and those who initiated in earlier settings and, although this had some ongoing impact, the relationship was not strongly related to current drug use patterns. Pharmaceutical opioid use was a key component of polydrug use among MIX participants, with 20% of the cohort reporting using illicitly-obtained pharmaceutical opioids in the month preceding baseline interview. Use of pharmaceutical opioids was however not sustained over time. The relationship between age and engagement in risk behaviours was examined using 10 years of data from the Australian Illicit Drug Reporting System, a national repeat cross-sectional survey of regular PWID recruited through needle and syringe programs, drug treatment and community settings. Older age was associated with decreased likelihood of engagement in a range of injecting-related and criminogenic risk behaviours. Injecting drug use among young people of African ethnicity was examined using MIX data and an additional qualitative study. Findings showed that injecting drug use (and substance use more broadly) and mental health are emerging issues among this community. Findings from this body of research inform the provision of harm reduction services which take into the account the key populations and patterns of drug use in the contemporary setting. Priority areas for future research include further research examining pharmaceutical opioid use among PWID, studies of substance use and mental health among resettled refugee youth, research into interventions to reduce injecting-related risk behaviours among younger PWID and additional longitudinal studies of PWID with a broader geographic focus.