*Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland;
†The Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland;
‡Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland;
§Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland;
‖Institute of Molecular Medicine, University of Texas Health Science Center, Houston, Texas;
¶Departments of Medicine and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin;
**Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina; and
††Hospital for Sick Children, University Health Network and University of Toronto, Toronto, Canada
Correspondence: Dr. W.H. Linda Kao, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St., Room W6513, Baltimore, MD 21205. Email: [email protected]
Received January 30, 2013
Accepted May 5, 2013
