[1] Mayo Clin, Div Hematol, Dept Internal Med, Coll Med, Rochester, MN 55905 USA
[2] Mayo Clin, Coll Med, Dept Hlth Sci Res, Div Epidemiol, Rochester, MN 55905 USA
[3] Mayo Clin, Coll Med, Dept Internal Med, Div Cardiovasc Dis, Rochester, MN 55905 USA
[4] Mayo Clin, Coll Med, Dept Hlth Sci Res, Div Biomed Stat & Informat, Rochester, MN 55905 USA