[1] Med Univ S Carolina, Inst Psychiat, Hollings Canc Ctr, Dept Psychiat & Behav Sci, Charleston, SC 29425 USA
[2] Med Univ S Carolina, Dept Pulm & Crit Care Med, Charleston, SC 29425 USA
[3] Med Univ S Carolina, Dept Biostat Bioinformat & Epidemiol, Charleston, SC 29425 USA
[4] Univ Alabama, Dept Epidemiol & Int Hlth, Birmingham, AL USA