[1] Duke Univ, Dept Anesthesiol, Crit Care & Perioperat Populat Hlth Res CAPER Uni, Durham, NC 27710 USA
[2] Duke Univ, Dept Populat Hlth Sci, Durham, NC 27710 USA
[3] Duke Univ, Sch Med, Durham, NC 27710 USA
[4] Univ Washington, Dept Biostat, Seattle, WA 98195 USA
[5] Univ Washington, Dept Neurol Surg, Seattle, WA 98195 USA
[6] Univ Calif San Francisco, Brain & Spinal Injury Ctr, San Francisco, CA 94143 USA
[7] Duke Univ, Dept Anesthesiol, DUMC 3094, Durham, NC 27710 USA
[8] Duke Univ, Dept Neurosurg, Durham, NC 27710 USA
[9] Univ Cincinnati, Dept Neurol & Rehabil Med, Cincinnati, OH USA
[10] Univ Michigan, Dept Emergency Med, Ann Arbor, MI 48109 USA
[11] Univ Washington, Dept Anesthesiol & Pain Med, Seattle, WA 98195 USA
[12] Duke Univ, Dept Neurol, Durham, NC 27710 USA
[13] Duke Univ, Dept Med, Durham, NC 27710 USA
[14] Duke Univ, Dept Biostat & Bioinformat, Durham, NC 27710 USA