CROSS-CULTURAL ADAPTATION AND VALIDATION OF THE TRADITIONAL CHINESE VERSION OF THE CORE OUTCOME MEASURES INDEX FOR PEOPLE WITH LOW BACK PAIN IN HONG KONG

Purpose: The Core Outcome Measures Index (COMI) is a multidimensional tool designed to assess the changes in health status of individuals with low back pain (LBP) over time as reported by them. It has been validated and translated into several languages. The objective of this study was to translate COMI into traditional Chinese and test its reliability and validity among the Cantonese-speaking people with LBP in Hong Kong. Methods: The COMI was translated into traditional Chinese following standard procedures and avoiding region-specific terminology. A total of 120 Cantonese-speaking individuals with LBP from The Hong Kong Polytechnic University were recruited. Participants completed a baseline translated COMI questionnaire online. After two-three days, a second set of online questionnaires, including the translated COMI, the traditional Chinese version of the Oswestry Disability Index (ODI), the Roland Morris Disability Questionnaire (RMDQ), and the EuroQol Five-Dimensional Five-Level Questionnaire (EQ-5D-5L), were administered to assess the reliability and validity of the translated COMI. Results: The standard Chinese version of COMI was successfully back-translated. There were low floor and ceiling effects, except for symptom-based well-being (floor effect) and disability (ceiling effect). In two rounds of surveys, the Cronbach's alpha values were 0.79 and 0.80, respectively, indicating sufficient internal consistency. The intraclass correlation coefficient [ICC(2,1)] for the overall score of the COMI was 0.91 (95% CI: 0.86-0.94), and for each item, it ranged from 0.7 to 0.88, demonstrating good test-retest reliability. The HK-COMI was confirmed to be a valid measure. Spearman's rho correlation tests showed a high correlation with ODI (rho=0.60) and EQ-5D-5L (rho=0.73), and a moderate correlation with RMDQ (rho=0.53). Conclusion: The traditional Chinese version of COMI is a valid and reliable tool for measuring the effectiveness of treatment for LBP among the Cantonese-speaking people in Hong Kong. Future studies should focus on assessing the sensitivity of this measure among the people with LBP in Hong Kong.