1. Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
2. School of Public Health, Imperial College London, London, United Kingdom
3. Mannheim Institute of Public Health, Social and Preventive Medicine, University of Heidelberg, Heidelberg, Germany
4. Instituto de Saúde Coletiva, Federal University of Bahia, Salvador, Brazil
5. Department of Community Medicine and Center for Cardiovascular and Respiratory Sciences, and
6. Department of Community Medicine, West Virginia University School of Medicine, Morgantown, West Virginia, USA