[1] Univ Michigan, Dept Internal Med, Div Gastroenterol & Hepatol, Med Sch, Ann Arbor, MI 48109 USA
[2] Michigan Integrated Ctr Hlth Analyt & Med Predict, Ann Arbor, MI USA
[3] Univ Michigan, Sch Med, Inst Healthcare Policy & Innovat, Ann Arbor, MI USA
[4] Univ Michigan, Dept Stat, Ann Arbor, MI 48109 USA
[5] Univ Michigan, Sch Med, Dept Surg, Ann Arbor, MI USA
[6] VA Ann Arbor Healthcare Syst, VA Ctr Clin Management Res, Ann Arbor, MI USA
[7] VA Ann Arbor Med Ctr, Dept Radiol, Ann Arbor, MI USA