Development and Validation of the Korean Version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for Patients with Non-muscle Invasive Bladder Cancer: EORTC QLQ-NMIBC24

PURPOSE: We aimed to evaluate psychometric properties of the Korean version of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-NMIBC24 when applied to Korean non-muscle invasive bladder cancer (NMIBC) patients. MATERIALS AND METHODS: A total of 249 patients who underwent curative transurethral resection of bladder tumor (TURBT) for primary or recurrent NMIBC were asked to complete the Korean version of EORTC QLQ-C30 and -NMIBC24 questionnaires three times (preoperative, post-TURBT 3 months and 6 months). Linguistic validation and psychometric evaluation of the questionnaire was conducted. RESULTS: Multitrait scaling analysis confirmed satisfactory construct validity in five scales except the malaise scale. Internal consistency was good (Cronbach’s alpha ≥ 0.70) for the five scales except the malaise scale at the all three time points. Known-group comparison analyses showed better quality-of-life (QOL) scores in patients with higher performance status as expected, and better sexual function in men than women (p < 0.05). Most of the scales had low correlations (< 0.40) with the scales in QLQ-C30 showing divergent validity, except for malaise scale which showed higher correlations (0.42 to 0.60). Responsiveness to change was consistent with clinical implications over time after TURBT. CONCLUSION: The Korean version of the EORTC QLQ-NMIBC24 has good reliability and cross-cultural validity for measuring various QOL aspects that can be self-administered to Korean NMIBC patients undergoing TURBT.