[1] Duke Univ, Med Ctr, Dept Psychiat & Behav Sci, Box 90399, Durham, NC 27708 USA
[2] Oregon Hlth & Sci Univ, Dept Anesthesiol & Perioperat Med, 3181 SW Sam Jackson Pk Rd, Portland, OR 97239 USA
[3] Durham VA Med Ctr, Ctr Hlth Serv Res Primary Care, Durham, NC 27705 USA
[4] Duke Univ, Med Ctr, Dept Med, Box 2628, Durham, NC 27710 USA
[5] Mem Sloan Kettering Canc Ctr, 1250 First Ave, New York, NY 10065 USA
[6] Weill Cornell Med Ctr, New York, NY USA
[7] Duke Univ, Med Ctr, Dept Med, Box 3459, Durham, NC 27710 USA