A prospective study to validate the expanded timed get-up-and-go in a population with multiple sclerosis

Background Timed 25-foot walk (T25FW) test serves as gold standard in care of persons with multiple sclerosis (PwMS) and as walking measure of regulatory trials. Objective To validate and determine the clinical utility of Expanded Timed Get-Up and Go (ETGUG) as a disability measure in MS. Methods ETGUG intra-rater and inter-rater reproducibility was determined in 65 PwMS that were examined twice in two centres over 1-week. Values below the 5th and above the 95th percentile were considered minimally detectable change. A longitudinal cohort (32.4 months) of 145 PwMS from New York State MS Consortium (NYSMSC) was used for clinical validation as a predictor of disability worsening measured by Expanded Disability Status Scale (EDSS). Results ETGUG and T25FW had noteworthy intra-rater and inter-rater reproducibility (Cronbach coefficient>0.949). One-week ETGUG difference ranged from 15.07% to -14.84% (5th and 95th percentile). Over the NYSMSC follow-up, PwMS had significant slowing in walking as measured by ETGUG (20.8 to 25.9s, p = 0.009) but not by T25FW. 15% ETGUG worsening had similar ability to predict EDSS worsening when compared to 20% T25FW worsening (AUC 0.596 vs. 0.552). Conclusion Over 32-month follow-up, PwMS experience slowing in ETGUG walking time but not in T25FW. Although the scoring may be more challenging, ETGUG could be more sensitive to change and provide more comprehensive measure of lower extremity performance and ambulation in PwMS.