[1] Stanford Univ, Dept Anesthesiol Perioperat & Pain Med, Stanford, CA 94305 USA
[2] Help Pain Med Network, San Mateo, CA 94403 USA
[3] Promises Profess Treatment Program, Los Angeles, CA USA
[4] Univ Calif San Francisco, Dept Inst Hlth & Aging, San Francisco, CA 94143 USA
[5] Georgia Profess Hlth Program Inc, Atlanta, GA USA