Validation of Perceived Physical Fatigability Using the Simplified-Chinese Version of the Pittsburgh Fatigability Scale

Abstract

Background: The Pittsburgh Fatigability Scale (PFS) was developed to capture fatigue and demand in a single tool, filling a gap that no validated questionnaire existed to measure perceived fatigability. Since fatigability is a more sensitive measure of a person’s susceptibility to fatigue, we validated the simplified-Chinese version of the PFS among Chinese community-dwelling older adults.Methods: The PFS was translated into the simplified-Chinese by the translation, retro-translation method. Internal consistency of the Physical subscale of the PFS was evaluated by Cronbach’s alpha. Convergent validity and discriminant validity were evaluated against physical performance measures (i.e., Short Physical Performance Battery & Timed Up and Go Test) and daily living performance (i.e., Barthel Index & Instrumental activity of daily living).Results: The simplified-Chinese version of PFS Physical scores showed strong internal consistency (Cronbach’s alpha=0.81). Higher PFS Physical scores were associated with worse physical performance, and daily living performance (|correlation coefficient| range: 0.36-0.56, p<.001). Age- and sex-adjusted PFS Physical scores had moderate to good overall discrimination for correctly classifying people by their physical performance and daily living performance (AUCs range 0.70-0.87, p<.001)Conclusions: The PFS simplified-Chinese version is a valid instrument to assess perceived physical fatigability in Chinese-speaking older adults with good convergent validity. Thus, the PFS, with low cost and greater feasibility, is a desired tool to measure fatigability in large population studies.