[1] George Washington Univ, Dept Med, 2150 Penn Ave NW,10-414, Washington, DC 20037 USA
[2] VA Ann Arbor Healthcare Syst, VA Hlth Serv Res & Dev Ctr Clin Management Res, Ann Arbor, MI USA
[3] Univ Michigan, Sch Med, Dept Internal Med, Michigan Ctr Hlth Analyt & Med Predict, Ann Arbor, MI USA