- Although there were shifts in the patterns of drugs injected reported by ANSPS participants over the period 1995-2010, participants in all survey years were most likely to report having last injected either heroin or methamphetamine.
- Heroin was the drug most recently injected by more than half of ANSPS respondents throughout the 1990s. From 2001, reports of heroin as the last drug injected declined to approximately one third of respondents.
- Methamphetamine was the drug most recently injected by around one quarter of survey respondents in all survey years, with the exception of the period 2001- 2006 when approximately one third of participants reported having last injected methamphetamine.
- The proportion of participants who most recently injected pharmaceutical opioids remained stable at 3% to 4% during the 1990s, but increased during the 2000s, reaching 16% in 2010.
- Reports of methadone as the last drug injected were highest in 1995 at 19%, but declined to a low of 3% in 1999 and 2000. Prevalence of methadone as the last drug injected ranged from 7% to 10% between 2002 and 2010.
- The proportion of participants who reported last injecting buprenorphine increased from 1% in 2002 (when data collection began) to 5% in 2006, with prevalence stable at 4%-5% since 2006.
- Reports of cocaine or anabolic steroids as the drug last injected remained low at 5% or less in the majority of years between 1995 and 2010.