Validation of an Arabic version of the Oswestry index in Saudi Arabia.

Abstract Objective The aim of this study was to adapt and validate the Tunisian version of the Oswestry Disability Index (ODI) within a Saudi Arabian population. Method The translation of items 8 and 10 taken out of the Tunisian version was conducted according to Beaton's method. Adaptations were made after a pilot study on 100 patients. The validation study included 100 patients suffering from chronic low back pain aged 18 to 65 years old. Intra-observer reliability was assessed using the intra-class coefficient (ICC). Spearman rank correlation coefficient, the Kruskall–Wallis test and factor analysis were used to evaluate construct validity (convergent and divergent validity). Internal consistency was assessed by Cronbach's alpha coefficient. Results One hundred Saudi patients were included in the study. Intra-observer reliability was excellent (ICC: 0.99). The correlations of the index with the VAS pain scale ( r  = 0.708), the Roland–Morris Low Back Pain Disability ( r  = 0.656), and the Quebec Back Pain Disability Scale ( r  = 0.792) suggest good construct validity. Factor analysis unveiled two main factors explaining a cumulative percentage variance of 63.5%. The first factor represents static activities and the second factor represents dynamic activities. Conclusion The Arabic version of the ODI adapted to the Saudi population has high metrological qualities. Further studies assessing its responsiveness to change should be conducted.