Validation of the Romanian Version of the Modified Fatigue Impact Scale (MFIS) in Multiple Sclerosis Patients

Fatigue is one of the most frequent and disabling symptoms in multiple sclerosis (MS), with major impact on quality of life. Reliable, culturally adapted instruments are essential for accurate assessment. To validate the Romanian version of the Modified Fatigue Impact Scale (MFIS) in MS patients. We conducted a cross-sectional study of 30 patients diagnosed according to the revised McDonald criteria. Participants had a mean age of 35.5 years; 66.7% were women. The MFIS was translated and culturally adapted using a standardized forward–backward procedure. Psychometric evaluation included internal consistency, construct validity (exploratory factor analysis and correlations with clinical variables), and discriminative validity (ROC analysis). The Romanian MFIS showed good internal consistency (Cronbach’s alpha = 0.821). Sampling adequacy was acceptable (KMO = 0.646; Bartlett p < 0.001). Exploratory factor analysis suggested a two-factor solution explaining 68.3% of the variance, with a weaker contribution from the psychosocial domain; given the small sample, this structure should be considered preliminary. MFIS scores correlated significantly with disability as measured by EDSS. In ROC analyses, EDSS demonstrated good discrimination of clinically relevant fatigue (AUC = 0.848, 95% CI 0.653–1.000; p = 0.05), whereas demographic variables did not. The Romanian MFIS is the first culturally adapted and validated version available for Romanian MS patients. It is a reliable tool for assessing multidimensional fatigue and can support both clinical use and integration into multicenter research. However, findings regarding its factorial structure are preliminary and require confirmation in larger, more diverse cohorts and responsiveness to change.