Background The Spine Functional Index (SFI) is a patient reported outcome measure with sound clinimetric properties and clinical viability for determination of whole-spine impairment. To date, no validated Turkish version is available.
Objectives The purpose of this study is to cross-culturally adapted the SFI for Turkish-speaking patients (SFI-Tk) and determine the psychometric properties of reliability, validity and factor structure in a Turkish population with spine problems.
Methods The SFI English version was culturally adapted and translated into Turkish using a double forward and backward method according to established guidelines. Patients (n=l32 neck region, n=153 low back region, 73% female, age 45±1) with spine disorders completed the SFI-Tk at baseline and after a seven day period for test-retest reliability. For criterion validity the Turkish version of the Functional Rating Index (FRI) was used plus the Neck Disability Index (NDI) and the Oswestry Disability Index (ODI) for back patients. Additional psychometric properties were determined for internal consistency (Chronbach's α), criterion validity and factor structure.
Results There was a high degree of internal consistency (α=0.85, item range 0.80-0.88). The test-retest reliability was high (r=0.93,item range 0.75-0.95). The factor analysis demonstrated a one-factor solution explaining 24.2% of total variance. Criterion validity with the ODI was high (r=0.71, p<0.001), with FRI and NDI it was fair (r=0.52 and r=0.58, respectively). The SFI-Tk showed no missing responses with the “half-mark” option used in 11.75% of total responses by 77.9% of participants. Measurement error from SEM and MDC90 were respectively 2.96% and 7.12%.
Conclusions The SFI-Tk demonstrated a one-factor solution and is a reliable and valid instrument. The SFI-Tk consists of simple and easily understood wording and may be used to assess spine region musculoskeletal disorders in Turkish speaking patients.
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Disclosure of Interest None declared