Can we trust self-reported walking distance when determining EDSS scores in patients with multiple sclerosis? The...

In multiple sclerosis (MS), the Expanded Disability Status Scale (EDSS) reflects disease severity. Although parts of the EDSS are dependent on actual walking distance, self-reported statements are often applied.

The purpose of the present study was, therefore, to compare self-reported walking distance to actual walking distance to outline how this influences EDSS scoring.

MS patients with EDSS 4.0-7.5 (n = 273) were included from the Danish MS hospitals rehabilitation study (n = 427). All patients subjectively classified their maximal walking distance according to one of seven categories (>500; 300-499; 200-299; 100-199; 20-99; 5-19; 0-4 m). Subsequently, actual maximal walking distance was assessed and EDSS was determined from both self-reported walking distance (EDSS_self-report) and actual walking distance (EDSS_actual).

In 145 patients (53%), self-reported walking distance was misclassified when compared to the actual walking distance. Misclassification was more frequent in patients using walking aids (64% vs. 44%, p < 0.05) and in patients with primary progressive MS (69%, p < 0.05). Misclassification of walking distance corresponded to incorrect EDSS scores (EDSS_self-report vs EDSS_actual) of ⩾0.5 point in 24%.

In MS patients with EDSS 4.0-7.5, 53% misclassified their walking distance yielding incorrect EDSS scores in 24%. Therefore, correct EDSS determination must be based on measurement of actual walking distance.