Objective: The aim of this study is a cross-cultural adaptation and validation of the modified fatigue impact scale for Portuguese (MFIS-BR).
Method: The MFIS was translated to Portuguese and re-translated to English. Two pilot studies had been carried through to obtain the MFIS-BR, which was applied to 57 consecutive stable MS patients and 45 healthy controls. The retest was applied 30 days later.
Results: In analyzing the statistics the internal consistency reability was similar to the original scale (0.74-0.86). The MFIS-BR showed ability to identify the different groups. Concerning the reliability the interclass correlation coefficient showed an excellent agreement (0.264-1.0).
Conclusion: The MFIS-BR fills the criteria of applicability, sensibility which are similar to the original version.