Validation of the Parkinson Fatigue Scale in Chinese Parkinson's disease patients

OBJECTIVE Fatigue is a common nonmotor symptom in Parkinson's disease (PD); however, the Parkinson's disease fatigue scale (PFS), which is designed to measure fatigue in PD, has not been validated in China. The aim of this study was to determine the validity and reliability of the Chinese version of the PFS in PD patients. METHODS A total of 115 PD patients were evaluated at baseline and after 7 days. Assessments included the PFS, the Fatigue Severity Scale (FSS), and scales assessing motor, cognition, depression, and anxiety. Acceptability was assessed in terms of the rate of missing data and floor and ceiling effects. Cronbach's alpha was calculated to determine internal consistency. Test-retest reliability was assessed using the intraclass correlation coefficient (ICC). Spearman's rank correlation coefficients were used to calculate convergent and divergent validity between PFS scores and scales assessing clinical characteristics. RESULTS No data were missing for the PFS. Compared with the original scoring method, the binary scoring method had relatively large floor effects (5.21% vs. 17.39%) and ceiling effects (0.90% vs. 4.31%). The internal consistency and test-retest reliability of the PFS were satisfactory (original scoring method: Cronbach's alpha = 0.97, ICC = 0.94; binary scoring method: Cronbach's alpha = 0.94, ICC = 0.94). The PFS score exhibited strong convergent validity with FSS score (correlation coefficient = 0.87). PFS score was weakly to moderately correlated with disease duration and with measures of disease stage, motor function, depression, and anxiety (range of correlation coefficients: 0.25-0.48). There was no significant correlation between PFS score and either onset age or MoCA score (range of correlation coefficients: -0.05 to 0.12). CONCLUSION The Chinese version of the PFS is a valid measure for assessing fatigue in PD.