Psychometric properties of the Fatigue Assessment Scale (FAS) in women with breast problems

To examine the usefulness of the Fatigue Assessment Scale (FAS) in women with benign breast problems (BBP) and women with early stage breast cancer (BC). Women with a palpable lump in the breast or an abnormality on a screening mammography (N = 560) completed the FAS (four time points) and measures of anxiety, depressive symptoms, neuroticism, and fatigue. The FAS appeared to have a good fit in the total population (Comparative Fit Index (CFI) =.96; X-2 ((29)) = 104.5; p<.001; Nonnormed Fit Index (NNFI)=.95; Root Mean Square Error of Approximation (RMSEA) = .091), the BC group (CFI = .95; X-2 ((32)) = 69.6, p < .001; NNFI = .91; RMSEA = .090), and the BBP group (CFI = .95; X-2 ((34)) = 99.9, p < .001; NNFI = .92; RMSEA = .105). The internal consistency (.89 total group) and the test-retest reliability (BBP group; r = .88 three months interval) were good. The FAS was a distinct factor from depressive symptoms, neuroticism, and state anxiety. In conclusion, the FAS has good reliability and validity in women with breast problems and measures fatigue without substantial overlap with depressive symptoms, state anxiety, and neuroticism