Validation and cross cultural adaptation of the Sinhala Version of Quebec Back Pain Disability Scale (QBDS)

Abstract

Attached

Objectives: To translate Quebec Back Pain Disability Scale(QBDS) to Sinhala language, and to validate the Sinhala version of QBDS among Sinhala speaking people. Methods: We translated QBDS in to Sinhala language then back translated it to English. All the steps of cross cultural adaptation process were followed and the translated pre-final Sinhala version was pre-tested among 20 participants to prepare the final Sinhala version. The final Sinhala version QBDS was tested among 138 patients with diagnosed back disorders at the time of the study and 124 people without back disorder (comparison group). Content validity was assured by a multidisciplinary team. In addition, correlation between Sinhala version of QBDS and Sinhala version of SF-36 was assessed by determining Pearson correlation coefficients. The Student’s t-test and Cronbatch alpha coefficient were used to check the score difference of both tools and internal consistency reliability of Sinhala version of QBDS. Results: Final Sinhala version of QBDS significantly correlated with Sinhala version SF -36 quality of life questionnaire [r=-0.75 (r2=0.57), p<0.05] indicating very good construct validity. Internal consistency reliability for the Sinhala version reached a Cronbach’s alpha coefficient of 0.91 indicating very good internal consistency reliability. Conclusions: The Sinhala translation of the QBDS provides an easy to understand; reliable and valid condition specific outcome measure of disability related to Low Back Pain among Sinhala speaking population and is recommended for use in Sri Lanka.