translation, cross-cultural adaptation and psychometric properties of the persian version of patient-specific functional scale in patients with chronic low back pain

Objectives: the major emphasis of physical therapy in patient evaluation is the assessment of physical function, and the patient-specific functional scale (psfs) is one of the most commonly used instruments for this purpose. therefore, the present study aims to translate and cross-culturally adapt the psfs into persian and test its psychometric properties in patients with chronic low back pain (clbp).methods: the psfs was translated from english to persian and cross-culturally adapted in accordance with the study by beaton et al.  psychometric properties of 100 clbp patients were assessed. reliability (internal consistency and test-retest) was examined for 32 participants who completed the persian version of the psfs (psfs-p) twice with one week interval. construct validity was assessed against the persian versions of the oswestry disability index (odi-p) and the numerical pain rating scale (nprs-p).results: the psfs-p showed excellent reliability (cronbach’s alpha=0.88, intraclass correlation coefficient [icc 3, 1] =0.95, 95% ci [0.87 to 0.98]). the construct validity analysis revealed a moderate negative correlation between psfs-p and nprs-p (r=-0.47) and a high negative correlation between psfs-p and odi-p (r=-0.61). the psfs-p showed no floor and ceiling effects.conclusion: the psfs-p has adequate psychometric properties and is applicable in both clinical settings and research involving the iranian population with clbp.