Injection drug use and methamphetamine smoking account for the majority of illicit drug-related harms and associated health care costs in Australia. We will establish the Methamphetamine and Injecting Drug Use Cohort Study (MIXMAX) to produce new evidence on the nature and extent of these harms and the effectiveness of interventions to address them. MIXMAX will combine our existing SuperMIX cohort of people who inject drugs (established 2008, N=1328) with our VMAX cohort of people who smoke methamphetamine (established 2016, N=854) to generate the largest cohort of active drug users in Australia, providing a harmonised platform for data analysis to answer key questions in relation to drug-related harms and interventions to mitigate them. We will:
(1) Establish the incidence of key clinical outcomes, mortality and morbidity including poor mental health, overdose, blood borne viral infections, injecting-related injuries and disease, and chronic diseases such as chronic obstructive pulmonary disease (COPD).
(2) Determine the effectiveness of existing and novel health service interventions, such as drug treatment, take-home naloxone and supervised injecting facilities on improving health outcomes and supporting long-term cessation from drug use, and
(3) Evaluate the impact of syndemic and structural factors such as homelessness and imprisonment on these outcomes.
Our new cohort design allows direct comparison of trajectories of the two types of illicit drug use that drive most of the costs and health burden attributed to illicit drugs. MIXMAX will allow us to provide the first comprehensive analysis of how best to reduce or eliminate these harms in the Australian rural and metropolitan context. Our study will provide unique data to inform and refine priority responses to prevent drug-related harms in a changing social, health and service delivery environment over the coming decade.