[1] Univ Pittsburgh, Grad Sch Publ Hlth, Dept Epidemiol, Pittsburgh, PA USA
[2] Mayo Clin, Div Epidemiol, Dept Hlth Sci Res, Rochester, MN USA
[3] Univ Minnesota, Sch Publ Hlth, Div Epidemiol & Community Hlth, Minneapolis, MN USA
[4] Mayo Clin, Dept Hlth Sci Res, Div Biomed Stat & Informat, Rochester, MN USA
[5] Univ Minnesota, Sch Med, Dept Lab Med & Pathol, Minneapolis, MN 55455 USA
[6] Univ Calif San Diego, Div Prevent Med, Dept Family & Prevent Med, La Jolla, CA 92093 USA