1. Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
2. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
3. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
4. Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
5. Department of Health Policy and Management, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
6. H. W. Odum Institute for Research in Social Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA