Mortality in the SuperMIX cohort of people who inject drugs in Melbourne, Australia: a prospective observational study.

AIMS: To measure mortality rates and factors associated with mortality risk among participants in the SuperMIX study, a prospective cohort study of people who inject drugs. DESIGN: A prospective observational study using self-reported behavioural and linked mortality data. SETTING: Melbourne, Australia. PARTICIPANTS/CASES: A total of 1209 people who inject drugs (67% male) followed-up between 2008 and 2019 for 6913 person-years (PY). MEASUREMENTS: We linked participant identifiers from SuperMIX to the Australian National Death Index and estimated all-cause and drug-related mortality rates and standardized mortality ratios (SMRs). We used Cox regression to examine associations between mortality and fixed and time-varying socio-demographic, alcohol and other drug use and health service-related exposures. FINDINGS: Between 2008 and 2019 there were 76 deaths in the SuperMIX cohort. Of those with a known cause of death (n = 68), 35 (51%) were drug-related, yielding an all-cause mortality rate of 1.1 per 100 PY [95% confidence interval (CI) = 0.88-1.37] with an estimated SMR of 16.64 (95% CI = 13.29-20.83) and overall accidental drug-induced mortality rate of 0.5 per 100 PY (95% CI = 0.36-0.71). Reports of recent use of ambulance services [adjusted hazard ratio (aHR) = 3.77, 95% CI =1.78-7.97] and four or more incarcerations (aHR = 2.78, 95% CI = 1.55-4.99) were associated with increased mortality risk. CONCLUSIONS: In Melbourne, Australia, mortality among people who inject drugs appears to be positively associated with recent ambulance attendance and experience of incarceration.

Profile and correlates of colorimetric reagent kit use among people who use ecstasy/MDMA and other illegal stimulants in Australia.

BACKGROUND: Colorimetric reagent kits can provide information about the compounds present in drug samples. This study aimed to identify patterns and correlates of colorimetric reagent kit use, as well as behavioural outcomes of testing, amongst people who use illegal stimulants in a context that lacks permanent government-sanctioned drug checking services. METHODS: Australians residing in capital cities who reported regularly using ecstasy/MDMA and/or other illegal stimulants ≥monthly in the past six months were recruited via social media and word-of-mouth from April-July 2019 (N = 792). Participants were asked about testing the contents and/or purity of illegal drugs, and features of last colorimetric reagent kit use. Logistic regression identified correlates of last using a kit (referent: no use of drug checking technology to test drug contents/purity in the past year). RESULTS: Over one-third (36%) reported testing drug contents and/or purity; of this group, 86% had last used a colorimetric reagent kit. On the last occasion, 52% reported someone else had conducted testing; 58% said testing occurred <24 h before planned drug use; and 24% reported testing for quantity of a substance. Correlates of drug checking comprised: being younger, male, past six-month use of new psychoactive substances, accessing community-based health services for alcohol or other drug reasons, selling drugs for cash profit, obtaining information from peers who had tried the drug, and searching online for reports of the drug by stamp/appearance. The majority (84%) tested a substance they had been sold and/or given as MDMA; of these, 87% detected MDMA. Of those who expected and detected MDMA, 29% and 11% reported results to their peers and dealer, respectively. CONCLUSION: People who use ecstasy/MDMA and/or other illegal stimulants seek out objective information about substance contents. In countries that lack permanent government-sanctioned drug checking services, it is important to acknowledge that people already engage in drug checking but with suboptimal technologies and without tailored specialist advice and education.