ABSTRACT Introduction The Uniting Medically Supervised Injecting Centre (MSIC) in Sydney (Australia) provides a supervised space for people to inject pre‐obtained drugs. We investigated injecting patterns among clients over time and the impact on overdose risk and client behaviours. Methods MSIC holds information on visit‐specific drug injected, overdose, and sanctions for disruptive behaviour. Data for May 2001 to December 2024 were analysed. Where amphetamines or opioids were injected, the study record was marked accordingly. Data were aggregated to an annual visit summary and drug categorised into Annual drug visits . Results In the study period the proportion of amphetamine injections increased from 2% to 7% between 2002 and 2011 to 50.1% in 2024 (Kendall's tau = 0.6, p < 0.001). The proportion of clients who exclusively inject amphetamines on‐site has significantly increased from 8.9% in 2001 to 43.9% in 2024 (Kendall's tau = 0.8, p < 0.001), as has the proportion injecting both amphetamines and opioids (5.6% in 2001 to 33.2% in 2024) (Kendall's tau = 0.7, p < 0.001). People who inject both opioids and amphetamines had a lower likelihood of overdose compared to those who injected exclusively opioids (adjusted OR 0.64 (95% CI 0.54, 0.75); p < 0.001). Incidents of challenging behaviour appear unrelated to amphetamine injection. Discussion and Conclusions There has been an increase in amphetamine injection at MSIC, with the most frequent service attenders most likely to report injecting both opioids and amphetamines. There has been no parallel increase in disruptive behaviour. Those exclusively injecting amphetamines do not attend the service frequently. Strategies to support opportunistic intervention are clearly warranted.
Bartlett et al. (2026) studied this question.