Abstract
Purpose
To cross-culturally adapt the Patient-Specific Functional Scale (PSFS) into Arabic language and to examine its measurement properties in patients with lower extremity musculoskeletal disorders.
Materials and methods
The original English version of the PSFS was cross-culturally adapted into modern standard Arabic language following Beaton's guidelines. Patients with lower extremity musculoskeletal disorders (N = 116) were recruited to examine the test-retest reliability, measurement error, floor and ceiling effects, and construct validity of the Arabic PSFS. Construct validity was tested by examining eight predefined correlational hypotheses.
Results
Participants in the current study indicated that the Arabic PSFS was clear and understandable. The Arabic PSFS had very good test-retest reliability (ICC = 0.86) with no floor or ceiling issues. The standard error of measurement and the minimal detectable change of the Arabic PSFS were 0.64 and 1.49 points respectively indicating acceptable measurement error. The majority of the predefined construct validity hypotheses (75%) were supported by the results justifying the construct validity of the Arabic PSFS.
Conclusions
The Arabic PSFS is a comprehensible and easy to use measure. The Arabic PSFS has very good test-retest reliability, acceptable measurement error, and evidence supporting its construct validity as measure of activity limitation in patients with lower extremity musculoskeletal disorders.