Cross-cultural adaptation, reliability and validity of the Turkish version of patient-spesific functional scale in patients with neck pain

Objective: Current clinical guidelines recommend to use both clinical and self-reported measurements for evaluation of chronic neck pain. Among the self-reported outcomes, Neck Disability Index (NDI) and Patient Specific Functional Scale (PSFS) are the most widely used and recommended instruments. The validity and reliability analyzes of NDI were done before in Turkish language. The purpose of our study was to determine the validity and reliability of PSFS which was not validated in Turkish language previously. Method: The PSFS has been translated into Turkish (PSFS-T) according to the current guidelines. Demographic data, quality of life, cervical range of motion, PSFS-T, NDI and global rating of change were recorded at the initial assessment. For the test-retest reliability analysis, the first 30 patients were called by phone. Intraclass correlation coefficient (ICC) was established for reliability analyzes. The correlations between PSFS-T and NDI was examined for the validity analysis. Results: The final form of PSFS-T was completed by 110 chronic neck pain patients (F:77, M:33). Test-retest reliability of PSFS-T was found good level (ICC: 0.85). The relationship between PSFS-T and NDI was found moderate level (p <0.05, rho: -0.578). Furthermore, reading books/newspapers, cleaning and carrying heavy things were reported by Turkish neck pain patients as the first three activities which are the most problematic for their daily activities of life. Conclusion: PSFS-T is a valid and reliable method of measuring outcome in patients with neck pain. Future studies should focus on the validity and reliability of PSFS-T in different populations.