Development of the State Trait Inventory of Cognitive Fatigue (STI-CF)

Abstract

Objective: To develop and investigate the psychometric properties of a subjective measure of cognitive fatigue---the State Trait Inventory of Cognitive Fatigue (STI-CF)---in community-dwelling older adults.;Participants and Methods: The STI-CF was developed and administered to non-demented, community-dwelling participants (N = 175), aged 65 and above, who were enrolled in the Central Control of Mobility in Aging study (CCMA). A principal component analysis (PCA) was performed to establish construct validity. Reliability statistics were utilized to establish internal consistency. Pearson correlation coefficients were used for convergent validity and to explore relationships between subscales and relevant outcome variables.;Results: A PCA yielded the expected four 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 relationship between cognitive fatigue and a subjective measure of general fatigue, even after controlling for the confound of depression. The trait subscales were correlated in the expected direction to relevant cognitive outcome variables.;Conclusion: The current 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. This inventory is unique because it assesses state and trait forms of cognitive fatigue as well as the related constructs of motivation, mental effort, and boredom. While cognitive fatigue is commonly studied in neurological populations, it is less understood in the older adult population. The STI-CF's relatively brief administration time (less than 10 minutes; M = 5.6, SD = 2.9) and strong psychometric properties allow it to be successfully utilized in both research and clinical settings. Future studies should establish the psychometric properties of this scale in other populations and examine its relationship with additional relevant cognitive and motor outcome variables.