Testing psychometric properties of the standard Chinese version of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 (EORTC QLQ-C30)

BACKGROUND: Because cancer is now the first and second leading causes of death in both of urban and suburban area in China, there are increasing demands for measurement tools to assess quality of life in Chinese cancer patients. The objective of this study was to evaluate the psychometric properties of the standard Chinese version of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire 30 (EORTC QLQ-C30, version 3.0). METHODS: The questionnaire was administered before, during, and after treatment of 143 patients with breast, gynecological, or lung cancer in six hospitals in China. RESULTS: Cronbach's alpha coefficients for multi-item scales were greater than 0.70 before and during treatment, except for the cognitive functioning scale. Multitrait scaling analysis showed that most of the item-scale correlation coefficients met the standards of convergent and discriminant validity. All scales and items exhibited good reproducibility, criterion-related validity, and construct validity. Score changes over time were observed in the following scales: physical, role, and social functioning; global quality of life; fatigue; nausea/vomiting. Score changes were also observed in the appetite loss item. CONCLUSION: The standard Chinese version of the EORTC QLQ-C30 is overall a valid instrument to assess the quality of life of Chinese cancer patients.