Brazilian version of the Multidimensional Fatigue Inventory for Parkinson’s disease

Abstract Introduction: The multidimensional fatigue inventory (MFI) has not been applied in Brazilian Parkinson`s disease (PD) population due to the lack of validation. Objective: The aim of this study was to cross-culturally adapt, to validate, and investigate the psychometric properties of Brazilian version of the MFI in PD. Method: Idiopathic PD individuals (N = 90) were recruited. The MFI was translated into Brazilian Portuguese using established forward-backward translation procedures, and the psychometric properties were evaluated. All individuals were assessed by socio-clinical questionnaire, Mini-Mental State Examination (MMSE), Unified Parkinson’s Disease Rating Scale (MDS-UPDRS Part I-IV), Hoehn-Yahr disability scale (HY), hospital anxiety and depression scale (HADS), fatigue severity scale (FSS), Parkinson Fatigue Scale (PFS-16) and MFI-PD/ BR with retest of the MFI-PD/BR after seven days. Results: The adaptation phase kept the same items of original MFI-PD. No data missing, floor nor ceiling effects were found. The overall Cronbach's alpha coefficient for the 20 items was 0.81, ranging from 0.73 to 0.81 for each of the five subscales. Bland and Altman analysis showed no systematic differences between assessments. The intraclass correlation coefficient test-retest was higher or equal 0.70 (p < 0.01) for the MFI-PD/BR score, which was moderately correlated with the HADS, MDS-UPDRS score (motor examination, motor and non-motor experiences of daily living and motor complications), FSS and PFS-16. It was revealed the MFI-PD/ BR > 55 points as cut-off point to indicate fatigued subjects with accuracy of 0.84 (p < 0.001). Conclusion: The MFI-PD/BR can be considered a valid and reproducible instrument for assessing PD-related fatigue.