[1] Univ Michigan, Addict Ctr, Dept Psychiat, Med Sch, Ann Arbor, MI USA
[2] Univ Michigan, Inst Healthcare Policy & Innovat, Ann Arbor, MI 48109 USA
[3] Univ Michigan, Dept Anesthesiol, Div Pain Med, Med Sch, Ann Arbor, MI 48109 USA
[4] VA Ctr Clin Management Res, Ann Arbor, MI USA
[5] Univ Michigan, Med Sch, Dept Surg, Ann Arbor, MI USA