[1] Oregon Hlth & Sci Univ, Dept Emergency Med, Sch Med, Portland, OR 97201 USA
[2] Oregon Hlth & Sci Univ, Sch Med, Dept Surg, Portland, OR 97201 USA
[3] Johns Hopkins Univ, Sch Publ Hlth, Johns Hopkins Ctr Injury Res & Policy, Baltimore, MD USA
[4] Univ Washington, Sch Med, Dept Surg, Seattle, WA 98195 USA