[1] Wake Forest Univ Hlth Sci, Winston Salem, NC USA
[2] Ctr Pain Relief, Charleston, WV USA
[3] Fox Chase Pain Management Associates, Jenkintown, PA USA
[4] Ctr Intervent Pain Management, St Louis, MO USA
[5] Pain Inst Tampa, Tampa, FL USA
[6] Pain Control Network, Louisville, KY USA
[7] Lowell Gen Hosp, Lowell, MA USA