[1] Univ Michigan, M SCORE, Dept Surg, Ann Arbor, MI 48104 USA
[2] Washington Univ, Sch Med, St Louis, MO USA
[3] Barnes Jewish Hosp, St Louis, MO 63110 USA
[4] Dartmouth Hitchcock Med Ctr, Lebanon, NH 03766 USA
[5] Harvard Univ, Sch Med, Boston, MA USA
[6] Massachusetts Gen Hosp, Boston, MA 02114 USA
[7] Univ Washington, Seattle, WA 98195 USA
[8] Univ Calif Los Angeles, Ctr Surg Outcomes & Qual, Los Angeles, CA USA