abstract
- PURPOSE: Quality of life (QOL) can be compromised in patients with bone metastases, and validated QOL instruments are required to accurately measure QOL outcomes in this population. This study investigated the validity, reliability and responsiveness of the EORTC QLQ-BM22 module with the EORTC QLQ-C15-PAL instrument in bone metastases. METHODS: The studied patients underwent palliative radiotherapy to bone metastases in the randomized NCIC CTG SC 23 trial. Multi-trait scaling analysis was performed to determine convergent and divergent validity among scales. Pearson coefficients were calculated to determine the correlation between items of the two instruments. The clinical validity and responsiveness of the QLQ-BM22 was tested by known group comparisons of different performance status and response to radiotherapy. RESULTS: 204 patients completed both questionnaires at baseline and 42day follow-up. On multi-trait scaling analysis, there was mixed evidence of construct validity (explained by the questionnaire format and population characteristics). There was little correlation between most QLQ-BM22 and QLQ-C15-PAL items (except for conceptually related scales) validating their complementary nature. There were statistically significant differences in all QLQ-BM22 scale scores in groups with KPS<80 vs. KPS⩾80 and three out of four QLQ-BM22 scale scores in "responders" vs. "non-responders" to radiotherapy. In patients who responded to radiotherapy, there were statistically significant differences in all QLQ-BM22 scale scores between baseline and follow-up. CONCLUSION: This study further validates the use of the QLQ-BM22 as a robust and sensitive instrument to assess QOL in patients with bone metastases treated with palliative radiotherapy.