[1] Univ N Carolina, Dept Psychiat, 170 Manning Dr,Campus Box 7305, Chapel Hill, NC 27599 USA
[2] Univ N Carolina, Dept Med, 170 Manning Dr,Campus Box 7305, Chapel Hill, NC 27599 USA
[3] Univ N Carolina, Lineberger Comprehens Canc Ctr, Chapel Hill, NC 27599 USA
[4] Univ N Carolina, Dept Biostat, Chapel Hill, NC 27599 USA
[5] Univ N Carolina, Dept Hlth Policy & Management, Chapel Hill, NC 27599 USA
[6] Univ N Carolina, HW Odum Inst Res Social Sci, Chapel Hill, NC 27599 USA