1. University of Sydney, School of Public Health, Sydney Medical School; Sydney Australia
2. National Institute of Public Health, Centre for Evaluation Research and Surveys; Cuernavaca Morelos Mexico
3. University of Oregon; Department of Anthropology; Eugene OR USA
4. University of Newcastle, Research Centre for Gender, Health and Ageing, Faculty of Health, Newcastle; Australia
5. World Health Organization Study on global AGEing and adult health (SAGE); Geneva Switzerland