Validity and Reliability of the Turkish Version of the Patient-Specific Functional Scale in Patients with Shoulder Pain: A Methodological Study

Abstract

Objective: The Patient-Specific Functional Scale (PSFS) is frequently used for the functional evaluation of patients. The Turkish validity and reliability of the PSFS in patients with shoulder pain has not yet been established. This study aimed to evaluate the validity and reliability of the Turkish PSFS in patients with shoulder pain.

Methods: This methodological study was conducted between December 2023 and August 2024 at Kütahya Health Sciences University Evliya Celebi Training and Research Hospital.. Patient-Specific Functional Scale, Quick Disability of the Arm, Shoulder and Hand Questionnaire (QuickDASH), and Shoulder Pain and Disability Index (SPADI) were administered to 101 patients with shoulder pain aged 18-65 years at the initial assessment. The test-retest assessment was performed by re-administering scales to 77 patients 7 days later. Internal consistency was assessed using Cronbach’s α. Intraclass correlation coefficient (ICC) was used to evaluate test-retest reliability. Convergent validity was assessed using Pearson correlation analysis.

Results: The PSFS demonstrated acceptable internal consistency (Cronbach’s α = 0.740) and test-retest reliability (ICC 2,1 = 0.670). No floor or ceiling effects were observed. The PSFS showed moderate correlation with QuickDASH (r = −0.418, P < .01) and weak correlation with SPADI (r = −0.354, P < .01). Additionally, the standard error of measurement was 0.84, and the minimum detectable change was 2.33.

Conclusion: This study indicates that the Turkish PSFS is a valid and reliable measurement tool. Due to its quick administration and patient-centered approach, PSFS can be preferred as a practical assessment tool in clinical and research settings for individuals with shoulder pain.

Cite this article as: Afşar E, Bağdatlı E, Gökpınar HH. Validity and reliability of the Turkish version of the patient-specific functional scale in patients with shoulder pain: A methodological study. Arch Health Sci Res. 2026, 13, 0293, doi: 10.5152/ArcHealthSciRes.2026.25293.