Expanded disability status scale progression assessment heterogeneity in multiple sclerosis according to geographical areas

Using placebo data from 3 randomized MS trials with uniform inclusion criteria, we investigated heterogeneity of EDSS progression by geographical areas. Our analysis revealed a significantly lower EDSS progression in Eastern European countries (10.8%) compared with Europe (13.1%) or USA/Canada (21.4%,p<0.001); EDSS improvement behaved the same way . This heterogeneity is not explained by differences of baseline variables. No differences were detected on more easily quantifiable measures, the T25FW or the MSFC. At a time when disease progression represents the target for future interventions in MS, establishment of more quantitative and objective outcomes remains a key priority of MS research.