[1] Duke Univ, Med Ctr, Dept Anesthesiol, Crit Care & Perioperat Populat Hlth Res CAPER Unit, Durham, NC USA
[2] North Carolina State Univ, Sch Social Work, Raleigh, NC USA
[3] Duke Univ, Sch Med, Dept Populat Hlth Sci, Durham, NC USA
[4] Univ Calif San Francisco, Dept Anesthesiol, San Francisco, CA USA
[5] Durham VA Healthcare Syst, Anesthesia Serv, Durham, NC USA
[6] Siriraj Hosp, Fac Med, Dept Anesthesiol, Bangkok, Thailand