1 Health Sciences, NORC at the University of Chicago, Bethesda, Maryland, USA.
2 Health Behavior, University of North Carolina at Chapel Hill Gillings School of Global Public Health, Chapel Hill, North Carolina, USA aseiden@live.unc.edu.
3 Health Behavior, University of North Carolina at Chapel Hill Gillings School of Global Public Health, Chapel Hill, North Carolina, USA.
4 Family Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA.