[1] Johns Hopkins Univ, Sch Med, Dept Surg, Div Acute Care Surg, Baltimore, MD 21205 USA
[2] Johns Hopkins Univ, Sch Med, Dept Med, Div Gen Internal Med,Evidence Based Practice Ctr, Baltimore, MD 21205 USA
[3] Johns Hopkins Univ, Sch Med, Dept Anesthesiol & Crit Care Med, Baltimore, MD 21205 USA
[4] Johns Hopkins Univ, Sch Med, Dept Emergency Med, Baltimore, MD USA
[5] Johns Hopkins Med, Armstrong Inst Patient Safety & Qual, Baltimore, MD USA
[6] Johns Hopkins Med, CSTOR, Baltimore, MD USA