Validation of the Arabic version of the Quebec Back Pain Disability Scale.

STUDY DESIGN: Validity and reliability of a back pain questionnaire.

OBJECTIVE: This study tested the psychometric properties of the Arabic version of the Quebec Back Pain Disability Scale (QDS).

SUMMARY OF BACKGROUND DATA: QDS is a questionnaire widely used to evaluate the level of disability in patients with low back pain. The questionnaire has been translated into Arabic but not tested in an Arabic population.

METHODS: A total of 148 patients with nonspecific low back pain were recruited in the Gaza Strip. Patients were asked to complete a questionnaire booklet containing the Arabic version of the QDS, the Oswestry Disability Index (ODI), the Numeric Pain Rating Scale (NPRS), and a Likert scale, which was repeated 1 week later. Weighted κ was used to measure test-retest reliability and Cronbach α for internal consistency. For construct validity, the Arabic version of the QDS and the ODI were correlated with Spearman correlation coefficient. For concurrent validity, the QDS, ODI, and NPRS were compared. For face and content validity, a Likert scale was used to assess whether it was understandable and comprehensive.

RESULTS: The QDS demonstrated good test-retest reliability κ = 0.86-0.98 (P < 0.001). Correlation between the items was excellent Cronbach α = 0.92; item-total correlation was good = 0.84-0.86. A positive relationship was found between Arabic versions of QDS, ODI, and NPRS, indicating adequate construct validity (P = 0.69, P < 0.01). A positive relationship was found between Arabic versions of QDS and ODI (r = 0.67, P < 0.01) and the NPRS (r = 0.61, P < 0.01). Face validity and content validity were deemed to be reasonable.

CONCLUSION: The study showed that the psychometric properties of the original QDS have been preserved when translated into Arabic and can be used to measure disability in Arabic societies.