The EORTC core quality of life questionnaire (QLQ-C30, version 3.0) in terminally ill cancer patients under palliative care: validity and reliability in a Hellenic sample.

In 1986, the European Organization for Research and Treatment (EORTC) initiated a research program to develop an integrated, modular approach for evaluating the quality of life of patients participating in international clinical trials. The questionnaire was designed to measure cancer patients' physical, psychological and social functions. The questionnaire is composed of 5 multiitem scales (physical, role, social, emotional and cognitive functioning) and 9 single items (pain, fatigue, financial impact, appetite loss, nausea/vomiting, diarrhea, constipation, sleep disturbance and quality of life). It was administered to the patients before the initiation of palliative treatment and then once again during the treatment. The validation of the questionnaire took place at Areteion Hospital, while the translation was conducted by the EORTC bureau. The final validation sample consisted of 120 cancer patients. The clinical variable assessed was the performance status. The aim of our study was to assess the applicability of this quality of life measurement on a Hellenic sample of cancer patients receiving palliative care. The results showed that the questionnaire was well accepted in the present patient population. In addition, the questionnaire was found to be useful in detecting the effectiveness of palliative treatment over time. The scale reliability was very good (pretreatment from 0.57-0.79, ontreatment from 0.56-0.75), especially for the functioning scale. In addition, very good validity was found in all the approaches used. Moreover, the factor analysis results in a 6-factor solution that satisfies the criteria of reproducibility, interpretability and confirmatory setting. Performance status showed an improvement (p < 0.0025) during the studied period. These results support that the QLQ-C30 (version 3.0) has proven to be a reliable and valid measure of the quality of life in Greek cancer patients receiving palliative care treatment.