1 Department of General Practice, University of Melbourne, Carlton, Vic, Australia.
2 Judith Lumley Centre, La Trobe University, Melbourne, Vic, Australia.
3 Centre for Primary Health Care and Public Health, Barts and the London School of Medicine and Dentistry, Queen Mary College, University of London, London, UK.
4 Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA.
5 Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK gene.feder@bristol.ac.uk.