Self-reported maximum walking distance in persons with MS may affect the EDSS

Abstract

BackgroundIn persons with MS (PwMS), the Expanded Disability Status Scale (EDSS) is used to monitor disability progression. Scores between 4.0 and 7.0 are determined by maximum walking distance. Self-estimation of this value is often employed in clinic settings. ObjectiveTo examine the accuracy with which PwMS estimate their walking distance, and observe subsequent changes to the EDSS. MethodsThis prospective cohort study recruited PwMS with previously recorded EDSS of 3.5–7.0. Participants estimated their maximum walking distance and then walked as far as they could along a pre-specified course. Each distance was converted to an EDSS score, the “estimated EDSS” and the “actual EDSS”. Chi-Square analysis was used to compare EDSS scores. Logistic regression was used to determine predictors of inaccurate estimations. ResultsOf the 66 PwMS in this study, 43.9% had a difference in the actual EDSS compared to the estimated EDSS. Median estimated EDSS was 4.75 (range 3.0–7.0); after walking assessment, median actual EDSS was 5.0 (range 3.0–7.0), which represented a significant difference [X2 (df 64, N=66)=206.9; p<0.001]. Actual EDSS decreased in 9 PwMS (13.6%) and increased in 20 PwMS (30.3%). Logistic regression did not find any demographic/disease characteristic to be predictive of this discrepancy. ConclusionSome PwMS do not accurately estimate maximum walking distance; only 56.1% of PwMS accurately estimated their actual EDSS.