1. Pain Treatment Centers of America, Little Rock, AR 72211, USA
2. The Spine & Nerve Center of The Virginias, Charleston, WV 25301, USA
3. University of Kansas Hospital, Kansas City, KS 66160, USA
4. The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
5. Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
6. Spine & Pain Institute of Florida, Lakeland, FL 33805, USA
7. Napa Valley Orthopaedic Medical Group, Napa, CA 94558, USA
8. Axis Spine Center, Coeur d'Alene, ID 83815, USA
9. Adena Health System, Chillicothe, OH 45601, USA
10. Florida Pain Institute, Melbourne, FL 32940, USA