[1] Univ Penn, Wharton Sch, Dept Stat, 400 Huntsman Hall,3730 Walnut St, Philadelphia, PA 19104 USA
[2] Moss Rehabil Res Inst, Brain Injury Neuropsychol Lab, Elkins Pk, PA USA
[3] Moss Rehabil Res Inst, TBI Rehabil Res Lab, Elkins Pk, PA USA
[4] Univ Wisconsin, Ctr Demog & Ecol, Madison, WI 53706 USA
[5] NYU, New York, NY USA
[6] Stanford Univ, Stanford Sch Med, Standard Prevent Res Ctr, Palo Alto, CA 94304 USA
[7] Univ Penn, Dept Med, Perelman Sch Med, Philadelphia, PA 19104 USA
[8] Univ Penn, Dept Med Eth & Hlth Policy, Perelman Sch Med, Philadelphia, PA 19104 USA
[9] Univ Penn, Dept Neurol, Perelman Sch Med, Philadelphia, PA 19104 USA
[10] Childrens Hosp Philadelphia, Sports Med & Performance Ctr, Philadelphia, PA 19104 USA
[11] Univ Penn, Dept Pediat, Perelman Sch Med, Philadelphia, PA 19104 USA