Psychometric analysis of the Multidimensional Fatigue Inventory in a sample of persons treated for myocardial infarction

Background and Purpose: Fatigue after myocardial infarction is a frequent and distressing symptom in the early recovery phase. The purpose of this study is to psychometrically evaluate the Multidimensional Fatigue Inventory (MFI-20). Methods: The MFI-20 was evaluated using Rasch analysis. Results: The result showed that the MFI-20 can be used to obtain a global score reflecting an underlying unidimensional trait of fatigue; a transformation of the summarized raw scale scores into interval scale scores could be made. Also, 4 of the 5 original dimensions separately fitted the Rasch model. Conclusions: Calculation of a global score increases the possibility of identifying persons experiencing fatigue after myocardial infarction, and using the MFI-20 dimension scores increases the possibility of determining each person's specific fatigue profile.