Development and Validation of the State-Trait Inventory of Cognitive Fatigue in Community-Dwelling Older Adults.

OBJECTIVE: To develop and validate a subjective measure of cognitive fatigue-the State-Trait Inventory of Cognitive Fatigue-in community-dwelling older adults. DESIGN: Scale development and test construction. SETTING: Community-dwelling older adults enrolled in a longitudinal cohort aging study. PARTICIPANTS: Participants (N=175) were healthy, English-speaking, community-dwelling adults, age ≥65 years. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: State-Trait Inventory of Cognitive Fatigue total, cognitive fatigue, motivation, mental effort, and boredom summation scores for both state and trait forms. RESULTS: Principal component analysis yielded the expected 4 components for both state and trait forms: cognitive fatigue, mental effort, motivation, and boredom. All components had good reliability. There was good convergent validity as measured by the strong positive relation between cognitive fatigue and a subjective measure of general fatigue, even after controlling for depressive symptoms. Greater subjective cognitive fatigue was associated with worse performance on measures thought to be more sensitive to aspects of executive functioning. CONCLUSIONS: This study developed and established the psychometric properties of a new instrument for the subjective measurement of cognitive fatigue for use in community-dwelling older adults. The State-Trait Inventory of Cognitive Fatigue's relatively brief administration time (<10min; mean, 5.6±2.9) and strong psychometric properties support its utility in both research and clinical settings. Future studies should establish the psychometric properties of this scale in other populations and examine its predictive utility for relevant clinical outcomes.

Psychometric properties of the Brief Fatigue Inventory in community-dwelling older adults.

OBJECTIVE: To investigate the psychometric properties of the Brief Fatigue Inventory (BFI) in community-dwelling older adults. DESIGN: Cross-sectional validation study. SETTING: Community based. PARTICIPANTS: Subjects (N=302) were nondemented older adults (mean age, 76.44 y; 54% women). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: BFI total, severity, and interference summation scores. RESULTS: A principal component analysis (PCA) yielded 2 factors, fatigue severity and interference, explaining 65.94% of the variance. Both factors had good reliability, with Cronbach alpha values of .867 for fatigue interference and .818 for fatigue severity. Higher fatigue scores were associated with older age and worse physical and cognitive functions. CONCLUSIONS: Fatigue is a common and debilitating symptom in the aging population. The current study provides novel findings in validating and establishing a bidimensional factor structure for the BFI in older adults. Severity and interference were differentially related to important health outcomes; therefore, using these subscales in addition to the total BFI score is recommended with older adults. Because of its relatively short administration time and established psychometric properties, the BFI can be successfully incorporated into longitudinal studies and clinical trials.