An outcome measure of functionality and pain in patients with low back disorder: A validation study of the Iranian version of low back outcome score

Abstract

Study Design: Cross-sectional study.Purpose: This study aimed to cross-culturally translate and validate the low back outcome score (LBOS) in Iran.Overview of Literature: Lumbar disc hernia (LDH) is the most common diagnoses of low back pain and imposes a heavy burden onboth individual and society. Instruments measuring patient reported outcomes should satisfy cetain psychometric properties.Methods: The translation and cross-cultural adaptation of the original questionnaire was performed using Beaton's guideline. A totalof 163 patients with LDH were asked to respond to the questionnaire at three points in time: preoperative and twice within 1-weekinterval after surgery assessments. The Oswestry disabilty index (ODI) was also completed. The internal consistency, test-retest,convergent validity, and responsiveness to change were assessed. Responsiveness to change also was assessed comparing patients'pre- and postoperative scores.Results: The mean age of the cohort was 49.8 years (standard deviation=10.1). The Cronbach's alpha coefficients for the LBOS atpreoperative and postoperative assessments ranged from 0.77 to 0.79, indicating good internal consistency. Test-retest reliability asperformed by intraclass correlation coefficient was found to be 0.82 (0.62-0.91). The instrument discriminated well between subgroupsof patients who differed in the Finneson-Cooper score. The ODI correlated strongly with the LBOS score, lending support to itsgood convergent validity (r =-0.83; p <0.001). Further analysis also indicated that the questionnaire was responsive to change (p <0.001).Conclusions: The Iranian version of LBOS performed well and the findings suggest that it is a valid measure of back pain treatmentevaluation among LDH patients.