Psychometric properties of the brief fatigue inventory in Greek patients with advanced cancer.

Abstract

To validate the Greek version of the Brief Fatigue Inventory (BFI-Gr) in a sample of cancer patients, the scale was translated with the "forward-backward" procedure to Greek. It was administered twice, at a three-day interval, to 102 eligible patients with cancer. Together with the BFI-Gr scale, the patients also completed the European Organization for Research and Treatment of Cancer QLQ-C30 (version 3.0) subscales of fatigue and emotional functioning, and the M. D. Anderson Symptom Inventory. The BFI-Gr had an overall Cronbach alpha for the nine items of 0.954. The assessment of the relationships between the BFI-Gr and the other measurements showed statistically significant correlations between all the assessed measurements (r values between 0.47 and 0.76, P<0.0005), except with the emotional subscale of the European Organization for Research and Treatment of Cancer scale. Factor analysis yielded a one-factor solution, explaining 73.6% of the variance. Interitem correlations were high and ranged from 0.567 to 0.882 (P<0.0005). The test-retest reliability of scale showed that the coefficient agreement was 0.901 (P<0.0005). Univariate analysis revealed significant correlations between hemoglobin and fatigue (r=-0.21, P=0.037), and between performance status (P<0.0005) and opioids (P=0.009). These results support that the BFI-Gr is an instrument with satisfactory psychometric properties, and is a valid research tool for cancer-related fatigue in Greek cancer patients.