Multi-site samples of injecting drug users in Edinburgh: prevalence and correlates of risky injecting practices.

AIMS: To estimate the frequency of injecting and prevalence of equipment sharing and other risky injecting practices among intravenous drug users (IDUs) and to identify correlates of these behaviours.
DESIGN: Three cross-sectional surveys of IDUs by face-to-face interview in the years 1992-94.
SETTING: Multiple treatment and non-treatment sites throughout the city of Edinburgh, Scotland, UK. PARTICIPANTS: Six hundred and thirty-four interviews of 480 IDUs who reported having injected a drug in the previous six months. MEASUREMENTS: Self-reports of drug-taking behaviours, service contact, sexual behaviour and HIV knowledge, and anonymous testing of saliva for HIV antibodies.
FINDINGS: Only 18% had injected at least daily. Thirty-five per cent had accepted or passed on used equipment. Eighty-five per cent of subjects recruited from non-treatment sites were receiving treatment for their drug taking. Multivariate analyses indicated that risky injecting was associated with a consistent history of sharing, polydrug injecting, injecting in prison, having recently started injecting, and recent experience of methadone detoxification.
CONCLUSIONS: Injecting frequency and equipment sharing have declined substantially in Edinburgh during the past 10 years and are low compared to other cities in the United Kingdom and elsewhere. These improvements have occurred in the context of remarkably high levels of drug treatment service contact. Our findings support the international evidence indicating that IDUs have modified their injecting habits significantly without completely eliminating this form of HIV risk. High levels of service contact in Edinburgh provide ample opportunities to instigate further HIV prevention measures which target identifiable subgroups of IDUs who persist in risky injecting.