Discriminative ability of fall efficacy scale international in Iranian people with multiple sclerosis

The discriminative validity of fall efficacy scale international (FES-I) in differentiating between fallers and non-fallers, levels of functional mobility, dynamic balance and disability has not been assessed in Persian speaking people with multiple sclerosis (MS).

To assess reliability, factor structure, construct and known group validity, sensitivity and specificity of FES-I for differentiating individuals with and without a history of fall and determining a cutoff point of the Persian version of the FES-I in people with MS.

One hundred thirty people with all subtypes of MS were included. The ability of FES-I in differentiating fall history was assessed using receiver operating characteristic (ROC). Also the FES-I score of groups based on expanded disability status scale (EDSS) 1-3.5 low and 4-6 moderate, time up and go (TUG) ≥14 sec and functional reach test (FRT) ≥25 cm were compared. The correlation between FES-I with EDSS, TUG, FRT and short form health survey (SF-36) was assessed.

The ROC curve analysis revealed that the FES-I could differentiate people with MS based on fall history at a cutoff score of 35.5. The area under the curve (AUC) was 0.86 (sensitivity 76%; specificity 95%). Significant difference was observed between the FES-I score of groups with moderate and low EDSS scores (d = 2.98), higher than 14 sec TUG (d = 2.18) and lower than 25 cm FRT(d = 2.53). Significant high correlation was observed between FES-I with TUG (r = 0.88), EDSS (r = 0.91), FRT (r = -0.83), SF-36 physical (r =  -0.87) and mental (r =  -0.70) subscales.

The Persian versions of the FES-I could differentiate people with MS with fall history, higher disability, lower functional mobility and balance deficiency.