[1] Michigan State Univ, Grand Rapids MERC, Program Emergency Med, Grand Rapids, MI USA
[2] Michigan State Univ, Dept Epidemiol, E Lansing, MI 48824 USA
[3] Michigan State Univ, Dept Neurol, E Lansing, MI 48824 USA
[4] Michigan State Univ, Dept Ophthalmol, E Lansing, MI 48824 USA
[5] Michigan State Univ, Emergency Med Residency Program, Lansing, MI USA
[6] Michigan State Univ, Ctr Med Studies, Borgess Res Inst, Kalamazoo, MI USA