Summary
This paper investigates the frequency of intravenous drug use in a cohort of people who inject drugs, and the decline in use over time. It provides an important indication of the effectiveness of current interventions at reducing the consumption of illicit drugs. Comparisons are made between the injection frequency of participants on or off Opioids Substitution Therapy (OST), and according to the settings in which drugs are most frequently purchased and used (eg street, house). This research found an overall movement away from street based drug purchasing and drug use, towards more activity in private settings. This has important implications for the harms experienced by people who inject drugs. Intravenous drug use was persistent, with only slow declines observed in the frequency of the cohort's overall use. Lower injection frequency was associated with use in private rather than public locations as well as the uptake of OST. (Foreword, edited)