Translation and validation of the Standard Chinese version of the EORTC QLQ-C30

The majority of quality of life (QOL) questionnaires have been developed and used in English-speaking or Western European countries. The aims of this study were to provide the Standard Chinese version of the European Organization for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC QLQ-C30 version 2.0), and evaluate its psychometric properties. The translation process included independent translation, back translation, a pilot test with gynecological cancer patients, and a review and approval by the original developers. Participants in the major study included gestational trophoblastic disease patients (n = 68), ovarian cancer patients (n = 105), and other types of gynecological cancer patients (n = 18). The average completion time of the Standard Chinese version was 8.1 +/- 2.9 min. All item-subscale correlation coefficients exceeded the criterion of item-convergent validity (r > 0.40) except item 1, 5, 20, and 25, and all items correlated significantly higher with their own subscale than with other subscales except item 1, 20, and 25. The correlation coefficients among all subscales were significant but modest (r = 0.40-0.70). Seven out of nine subscales met the minimal standards of reliability (Cronbach's alpha > 0.70). In conclusion, the Standard Chinese version of the EORTC QLQ-C30 is a valid instrument overall in assessing the QOL of Chinese gynecological cancer patients.