1. Health Protection Research Unit, Population Health Sciences University of Bristol Canynge Hall, 39 Whatley Road, Clifton Bristol BS8 2PS UK
2. National Public Health Speciality Training Programme, South West Bristol UK
3. Kirby Institute, University of South Wales Sydney Sydney Australia
4. National Drug and Alcohol Research Centre University of South Wales Sydney, Sydney, Australia
5. Department of Family Medicine and Emergency Medicine Université de Montréal and Research Centre of the Centre Hospitalier de l'Université de Montréal (CRCHUM) Quebec Canada