The EORTC breast cancer-specific quality of life questionnaire (EORTC QLQ-BR23): Translation and validation study of the Iranian version

The objective of this study was to test the reliability and validity of the Iranian version of the European Organization for Research and Treatment of Cancer (EORTC) Breast Cancer-Specific Quality of Life Questionnaire (QLQ-B R23). The English-language version of the questionnaire was translated into Persian (Iranian language) and its final form was approved by the EORTC St udy Group on Quality of Life and then it was used in this study. The questi onnaire was administered at two points in time to a consecutive sample of 1 68 newly diagnosed breast cancer patients and almost all of them (99%) foun d the questions easy to understand and acceptable. Cronbach's alpha coeffic ient for multi-item scales (to test reliability) ranged from 0.63 to 0.95 a t baseline and from 0.75 to 0.92 at follow-up administration of the questio nnaire. Validity analysis was performed using known-groups' comparison anal ysis. The results showed that all functional and symptom scales discriminat ed between sub-groups of patients differing in clinical status as defined b y their performance status and disease stage. In addition, all functional a nd symptoms scales detected change over time, as a function of changes in p atients' performance status. In general, the findings of this study indicat ed that the Iranian version of the EORTC QLQ-BR23 is a reliable and valid s upplementary measure of the quality of life in breast cancer patients and c an be used in clinical trials and studies of outcome research in oncology.