1. Health Behaviour Research Collaborative, School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia
2. Priority Research Centre for Health Behaviour, The University of Newcastle, Callaghan, NSW, Australia
3. Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
4. School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia
5. National Drug and Alcohol Research Centre, University of New South Wales, Sydney, NSW, Australia
6. Clinical Research Design, Information Technology and Statistical Services, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia