[1] Med Univ S Carolina, Div Biostat & Epidemiol, Charleston, SC 29425 USA
[2] Geisinger Hlth Syst, Ctr Hlth Res, Danville, PA 17822 USA
[3] Med Univ S Carolina, Ctr Digest Dis, Charleston, SC 29425 USA
[4] Med Univ S Carolina, Dept Pharm, Charleston, SC 29425 USA
[5] Med Univ S Carolina, Dept Psychiat, Charleston, SC 29425 USA