[1] Oregon Hlth & Sci Univ, Dept Med, Dept Med Informat & Clin Epidemiol, Oregon Evidence Based Practice Ctr, Portland, OR 97201 USA
[2] Dartmouth Hitchcock Med Ctr, Dept Anesthesiol, Pain Management Ctr, Lebanon, NH 03766 USA
[3] Univ Utah, Dept Anesthesiol, Pain Res Ctr, Salt Lake City, UT USA
[4] Univ Calif San Francisco, Sch Nursing, Dept Physiol Nursing, San Francisco, CA 94143 USA
[5] Mem Sloan Kettering Canc Ctr, Dept Psychiat & Behav Sci, New York, NY 10021 USA
[6] Beth Israel Deaconess Med Ctr, Dept Pain Med & Palliat Care, New York, NY 10003 USA