[1] Univ Pittsburgh, Dept Epidemiol, Pittsburgh, PA 15261 USA
[2] Rhode Isl Hosp, Providence, RI USA
[3] Mayo Clin, Rochester, MN USA
[4] Univ Pittsburgh, Med Ctr, Pittsburgh, PA 15261 USA
[5] Univ Utah, Dept Family & Prevent Med, Salt Lake City, UT 84112 USA