[1] JBSA Ft Sam Houston, US Army Inst Surg Res, Ft Sam Houston, TX 78234 USA
[2] Univ Texas Hlth Sci Ctr Tyler, Sch Community & Rural Hlth, Dept Epidemiol & Biostat, Tyler, TX 75708 USA
[3] JBSA Ft Sam Houston, Joint Trauma Syst, Ft Sam Houston, TX USA
[4] Uniformed Serv Univ Hlth Sci, Dept Med, Bethesda, MD USA
[5] JBSA Ft Sam Houston, Naval Med Res Ctr, Ft Sam Houston, TX USA