Study design: Validation of a translated, culturally adapted questionnaire.
Objectives: To translate and culturally adapt the Turkish version of the Oswestry Disability Index (ODI) (2.0), and to validate its use for assessing disability in Turkish patients with low back pain.
Summary of background data: The ODI is a reliable evaluation instrument for disability, but no validated Turkish version is available.
Methods: A total of 95 outpatients with low back pain were assessed by the ODI. Sixty-five of these patients were observed on a second occasion. Translation/retranslation of the ENG version of the ODI was done blindly and independently by four different individuals, and adapted by a team. Individuals were given the ODI and other scales (Visual Analog Scale, Schober Test, and the Roland-Morris Disability Questionnaire) on their first visit and a week later.
Results: Scores of the two ODIs were 27.10 (SD 16.22) on day 1 and 22.88 (SD 13.94) on day 7, with an intraclass correlation coefficient of r = 0.938 (P < 0.001). Cronbach's alpha was 0.918 (day 1) and 0.895 (day 7) in the validation. Concurrent validity, measured by comparing ODI responses with the results of Visual Analog Scale and Schober test, was r = 0.367 (P < 0.01), r = -0.068 (P = 0.591) for day 1, and r = 0.392 (P < 0.01), r = -0.041 (P = 0.745) for day 7, respectively. Construct validity, tested by determining the correlation between the Turkish ODI and the Turkish adaptation of the Roland-Morris Disability Questionnaire, yielded r = 0.815 (P < 0.001) on day 1 and r = 0.708 (P < 0.001) on day 7.
Conclusion: The Turkish version of ODI has good comprehensibility, internal consistency, and validity and is an adequate and useful instrument for the assessment of disability in patients with low back pain.