Purpose: The aim of our study was to undertake a prospective validation study of the Polish version of the European Organization for Research and Treatment of Cancer (EORTC) bone metastases (QLQ-BM22) module used alongside the EORTC core measure.
Methods: The translated module was pilot-tested according to the established EORTC guidelines. Patients with histological confirmation of malignancy and bone metastases, diagnosed by imaging studies, were eligible for the study. All patients filled out the Polish version of the QLQ-BM22 module in addition to QLQ-C30 and a demographic questionnaire. Standard validity and reliability analyses were performed.
Results: One hundred and fifty-five patients were enrolled into the study, including 94 women (60.7 %) and 61 men (mean age ± SD; 59.1 ± 12.1). Cronbach's alpha coefficients, range 0.68-0.93, showed positive internal consistency. Re-test was undertaken with fifty patients (32.3 %). Interclass correlations for the EORTC QLQ-BM22 ranged from 0.91 to 0.93 and proved sufficient test-retest reliability. Satisfactory convergent and discriminant validity in multi-trait scaling analyses was seen.
Conclusions: Our study provides new and robust evidence which shows that the Polish version of the QLQ-BM22 module is a valid and reliable instrument for measuring health-related quality of life in patients with bone metastases. It is suitable for use in clinical trials and in research.