Cross-cultural translation and psychometric testing.
To translate, culturally adapt, and validate the Oswestry Disability Index (ODI) version 2.0 for the French-Canadian population.
Many authors have recommended the administration of standardized instruments, rather than the creation of new scales, and advocate the adaptation of validated questionnaires in other languages. The application of these scales in different countries and by cultural groups necessitates cross-cultural adaptation. Many scales evaluate the functional incapacity resulting from low back pain. The ODI is among the most commonly used for this purpose.
The French-Canadian ODI (ODI-FC) was developed by cross-cultural adaptation following internationally recommended methodology: forward translation, back translation, expert committee revision, and clinical evaluation of the prefinal version. Psychometric testing was performed on 72 patients with chronic low back pain. The subjects were recruited from a physiatry department in a university hospital and from a private practice physiatry clinic. They came from the Montreal area. The psychometric testing included internal consistency (Cronbach α), test-retest reliability (intraclass correlation coefficient) with a time interval set at 48 hours, and construct validity, comparing the ODI-FC with the Roland-Morris Disability Questionnaire and the Quebec Back Pain Disability Scale (Pearson correlation coefficient).
In 44.4% of the subjects, the average duration of low-back pain varied between 1 and 5 years. Average score for the ODI-FC was 29.2. Good internal consistency was found (Cronbach α = 0.88). Reliability was excellent, with intraclass correlation coefficient = 0.92 (95% confidence interval, 0.87-0.95). Construct validity results revealed excellent correlations between the ODI and the Quebec Back Pain Disability Scale (r = 0.90) and between the ODI and the Roland-Morris Disability Questionnaire (r = 0.84).
Cross-cultural translation and adaptation of the ODI-FC were successful. Psychometric testing determined that the instrument was homogeneous, reliable, and valid. It could be employed in future clinical trials in Canada and possibly in other French-speaking countries.