1. Centre for Research on Drugs and Health Behaviour, Department of Social and Environmental Health Research; London School of Hygiene and Tropical Medicine; London UK
2. Department of Epidemiology; Lazio Regional Health Service; Rome Italy
3. New York University, College of Nursing; New York NY USA
4. School of Social and Community Medicine; University of Bristol; Bristol UK
5. National Drug and Alcohol Research Centre; University of New South Wales; Randwick Australia
6. Public Health Institute; Liverpool John Moores University; Liverpool UK
7. School of Health and Life Sciences, Glasgow Caledonian University; Glasgow and Health Protection Scotland; Glasgow UK
8. Kirby Institute; University of New South Wales, Sydney; Sydney Australia
9. School of Social Sciences, University of West of Scotland; Paisley UK
10. Department of Family and Emergency Medicine; University of Montreal; Montreal Canada