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.