The EORTC Quality of Life Questionnaire for patients with prostate cancer: EORTC QLQ-PR25. Validation study for Spanish patients

The EORTC Quality of Life (QL) Group has developed a questionnaire, the EORTC QLQ-PR25, for evaluating QL in prostate cancer. The aim of this study is to assess the psychometric properties of the EORTC QLQPR25 when applied to a sample of Spanish patients. One hundred and thirty-seven prostate cancer patients with localised disease who started radiotherapy with radical intention combined with or without hormonotherapy prospectively completed the EORTC QLQ-C30 and EORTC QLQ-PR25 questionnaires three times: on the first and last day of radiotherapy and in the follow-up period. Psychometric evaluation of the questionnaires' structure, reliability and validity was conducted. Multitrait scaling analysis showed that many of the item-scale correlation coefficients met the standards of convergent and discriminant validity. Exceptions appeared mainly in the scales for bowel symptoms and for hormonal-treatment-related symptoms. Cronbach's coefficients of the scales were good (0.72-0.86) for the urinary symptoms and sexual function scales but they were lower (< 0.70) for the bowel and hormonal treatment scales. Most scales of the EORTC QLQ-PR25 had low to moderate intercorrelations. Correlations between the scales of the QLQ-C30 and the module were generally low. Group comparison analyses showed better QL in patients with higher Performance Status. Changes in QL appeared throughout the measurements. These were in line with the treatment process. The EORTC QLQ-PR25 was a reliable and valid instrument when applied to a sample of Spanish prostate cancer patients. These results are in line with those of the EORTC validation study.