BMC Public Health 2009, 9:237 http://www.biomedcentral.com/1471-2458/9/237 59. Subramanian SV, Kawachi I: Whose health is affected by income inequality? A multilevel interaction analysis of contempora- neous and lagged effects of state income inequality on indi- vidual self-rated health in the United States. Health Place 2006, 12:141-156. 60. Lynch J, Harper S, Kaplan GA, Davey SG: Associations between income inequality and mortality among US states: the importance of time period and source of income data. Am J Public Health 2005, 95:1424-1430. 61. Oliver LN, Hayes MV: Does choice of spatial unit matter for estimating small-area disparities in health and place effects in the Vancouver Census Metropolitan Area? Can J Public Health 2007, 98(Suppl 1):S27-S34. Pre-publication history The pre-publication history for this paper can be accessed here: http://www.biomedcentral.com/1471-2458/9/237/pre pub Publish with Bio Med Central and every scientist can read your work free of charge "BioMed Central will be the most significant development for disseminating the results of biomedical research in our lifetime." Sir Paul Nurse, Cancer Research UK Your research papers will be: available free of charge to the entire biomedical community peer reviewed and published immediately upon acceptance cited in PubMed and archived on PubMed Central yours — you keep the copyright Submit your manuscript here: http://www.biomedcentral.com/info/publishing_adv.asp BioMedcentral Page 11 of 11 (page number not for citation purposes)