[1] Univ Penn, Perelman Sch Med, Natl Clinician Scholars Program, Philadelphia, PA 19104 USA
[2] Univ Penn, Leonard Davis Inst Hlth Econ, Perelman Sch Med, Philadelphia, PA 19104 USA
[3] Univ Penn, Div Gen Internal Med, Perelman Sch Med, Philadelphia, PA 19104 USA
[4] Univ Penn, Dept Emergency Med, Perelman Sch Med, Philadelphia, PA 19104 USA
[5] Univ Penn, Dept Biostat, Perelman Sch Med, Philadelphia, PA 19104 USA
[6] Univ Penn, Dept Epidemiol, Perelman Sch Med, Philadelphia, PA 19104 USA
[7] Univ Penn, Dept Informat, Perelman Sch Med, Philadelphia, PA 19104 USA
[8] Corporal Michael J Crescenz Vet Affairs Med Ctr, Dept Med, Philadelphia, PA 19104 USA