1. a School of Public Health & Community Medicine , University of New South Wales , Sydney , Australia
2. b Drug Health Service , Royal Prince Alfred Hospital , Sydney , Australia
3. c The Kirby Institute (formerly the National Centre in HIV Epidemiology and Clinical Research) , University of New South Wales , Sydney , Australia
4. d Sydney Medical School , University of Sydney , Sydney , Australia
5. e National Drug and Alcohol Research Centre , University of New South Wales , Sydney , Australia
6. f Kirketon Road Centre, Sydney , Australia
7. g Redfern Harm Minimisation Clinic , Local Health District, Sydney , Australia