Affiliation: | (1) Pain research group, multidisciplinary pain clinic of iran jahad danesh gahi, no 31, karimkhan zand ave, shahid hosseini alley, Tehran, Iran;(2) Department of physical medicine and rehabilitaton, shiraz medical school, zand avenue, Shiraz, Iran;(3) Department of biostatistics, shiraz medical school, zand avenue, Shiraz, Iran |