Translation and validation of the Cancer-Related Fatigue Scale in Greek in a sample of patients with advanced prostate cancer

OBJECTIVE To translate and validate the Cancer-Related Fatigue (CRF) Scale in the Greek language. DESIGN A cross-sectional descriptive design was used in order to translate and validate the CRF Scale in Greek. Factor analyses were performed to understand the psychometric properties of the scale and to establish construct, criterion and convergent validity. SETTING Outpatients' oncology clinics of two public hospitals in Cyprus. PARTICIPANTS 148 patients with advanced prostate cancer undergoing chemotherapy. RESULTS The Cancer Fatigue Scale (CFS) had good stability (test-retest reliability r=0.79, p<0.001) and good internal consistency (Cronbach's α coefficient for all 15 items α=0.916). Furthermore, the Kaiser-Meyer-Olkin Measure of Sampling Adequacy (KMO value) was found to be 0.743 and considered to be satisfactory (>0.5). The correlations between the CFS physical scale (CFS-FS scale) and the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 physical subscales were found to be significant (r=-0.715). The same occurred between CFS cognitive and EORTC cognitive subscale (r=-0.579). Overall, the criterion validity was verified. The same occurs for the convergent validity of the CFS since all correlations with the Global Health Status (q29-q30) were found to be significant. CONCLUSIONS This is the first validation study of the CRF Scale in Greek and warrant of its use in the assessment of prostate cancer patient's related fatigue. However, further testing and validation is needed in the early stages of the disease and in patients in later chemotherapy cycles.