[1] Univ Florida, Coll Med, Dept Emergency Med, Jacksonville, FL USA
[2] Univ Alabama Birmingham, Sch Med, Dept Emergency Med, Birmingham, AL USA
[3] Univ Alabama Birmingham, Dept Epidemiol, Birmingham, AL USA
[4] Univ Alabama Birmingham, Sch Med, Dept Med, Birmingham, AL USA
[5] Weill Cornell Med Coll, Dept Med, New York, NY USA
[6] Univ Florida, Dept Epidemiol, Gainesville, FL USA
[7] Mayo Clin, Dept Family Med, Jacksonville, FL 32224 USA
[8] Univ Alabama Birmingham, Dept Biostat, Birmingham, AL USA
[9] Univ Alabama Birmingham, Dept Emergency Med, 619 19th St South,OHB 251, Birmingham, AL 35249 USA