1. Department of Epidemiology; Johns Hopkins Bloomberg School of Public Health; Baltimore Maryland USA
2. Welch Center for Epidemiology, Prevention and Clinical Research; Johns Hopkins University; Baltimore Maryland USA
3. Division of General Internal Medicine; Johns Hopkins School of Medicine; Baltimore Maryland USA
4. Department of Surgery, Medicine and Social Sciences, Social and Cardiovascular Epidemiology Research Group, School of Medicine; University of Alcala; Madrid Spain
5. Department of International Health; Johns Hopkins Bloomberg School of Public Health; Baltimore Maryland USA
6. Department of Family and Preventive Medicine; University of California San Diego School of Medicine; California USA