1. John Hunter Hospital, Hunter New England Local Heath District, New Lambton Heights, NSW 2305, Australia
2. Hunter Medical Research Institute, Equity in Health and Wellbeing, New Lambton Heights, NSW 2305, Australia
3. School of Health Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
4. Department of Rural Health, University of Newcastle, Port Macquarie, NSW 2444, Australia
5. School of Medicine and Public Health, The University of Newcastle, Callaghan, NSW 2308, Australia