[1] Univ Alabama, Dept Emergency Med, Birmingham, AL 35294 USA
[2] Univ Alabama, Ctr Outcomes & Effectiveness Res & Educ, Birmingham, AL USA
[3] Univ Alabama, Dept Med, Div Prevent Med, Birmingham, AL USA
[4] Emory Univ, Sch Med, Dept Emergency Med, Atlanta, GA USA
[5] William Beaumont Hosp, Dept Emergency Med, Royal Oak, MI 48072 USA
[6] Birmingham VA Med Ctr, Deep S Ctr Effectiveness Res, Birmingham, AL USA
[7] Univ Alabama, Dept Med, Hlth Serv & Outcomes Res Training Program, Birmingham, AL 35294 USA