[1] Univ N Carolina, Dept Med, Chapel Hill, NC 27515 USA
[2] Univ Pittsburgh, Dept Epidemiol, Pittsburgh, PA 15261 USA
[3] Univ Pittsburgh, Dept Biostat, Pittsburgh, PA 15261 USA
[4] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA
[5] Univ Michigan, Dept Internal Med, Ann Arbor, MI 48109 USA
[6] Univ Toronto, Toronto Ctr Liver Dis, Toronto, ON, Canada
[7] NIDDK, Liver Dis Res Branch, NIH, Bethesda, MD 20892 USA