[1] Affordable Pain Management, 5600 N Sheridan Rd 104, Chicago, IL 60660 USA
[2] VA Boston Healthcare Syst, Anesthesiol Crit Care & Pain Med Serv, 150 S Huntington Ave, Boston, MA 02130 USA
[3] Penn State Coll Med, Pain Med Div, Dept Anesthesiol, 500 Univ Dr,POB 850, Hershey, PA 17033 USA
[4] Southern Rehabil Inst, 29 Byron St,POB 7549, Christchurch 8240, New Zealand