1 Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC.
2 Health Network America, Tinton Falls, NJ.
3 Gradient Corporation, Cambridge, MA; Department of Epidemiology, Harvard School of Public Health, Cambridge, MA.
4 Gradient Corporation, Cambridge, MA.
5 Division of Epidemiology, Biostatistics and Environmental Health, School of Public Health, University of Memphis, Memphis, TN.
6 Department of Medicine, the Department of Public Health Sciences, and the Environmental Biosciences Program, Medical University of South Carolina, Charleston, SC. Electronic address: mohrlc@musc.edu.