The Clinical Meaning of Walking Speed as Measured by the Timed 25-Foot Walk in Patients With Multiple Sclerosis

Abstract

IMPORTANCE Walking impairment, a common clinical manifestation of multiple sclerosis (MS), is often measured in clinical practice and clinical trials using the Timed 25-Foot Walk (T25-FW). OBJECTIVE To evaluate the relationship between walking speed measured by the T25-FW and the Physical Component Summary (PCS) score of the 36-Item Short Form Health Survey (SF-36) to better understand the clinical meaning of T25-FW walking speed in MS. DESIGN, SETTING, AND PARTICIPANTS We retrospectively analyzed data from 3 clinical trials (Natalizumab Safety and Efficacy in Relapsing-Remitting Multiple Sclerosis [AFFIRM], Safety and Efficacy of Natalizumab in Combination With Interferon Beta-1a in Patients With Relapsing-Remitting Multiple Sclerosis [SENTINEL], and International MS Secondary Progressive Avonex Controlled Trial [IMPACT]) that included T25-FW and SF-36 scores as outcomes in patients with MS. Patients had secondary-progressive MS and an Expanded Disability Status Scale score of 3.5 to 6.5 or relapsing-remitting MS and an Expanded Disability Status Scale score of 0 to 5.0. MAIN OUTCOMES AND MEASURES We used Spearman rank correlation and Pearson product moment correlation (r) and descriptive statistics to evaluate retrospectively the relationship between the SF-36 PCS score and T25-FW walking speed at baseline and the 2-year changes from baseline. RESULTS Among all 2549 patients from the 3 trials, walking speed and SF-36 PCS score at baseline were significantly correlated (n = 2333; r = 0.48; P < .001). In placebo-treated patients at 2 years, the percentage of change from baseline in walking speed was significantly correlated with the change from baseline in SF-36 PCS score (r = 0.35; P < .001). Significant correlations between the change in SF-36 PCS scores and the percentage of change in walking speed at 2 years also were observed in groups receiving active treatment (r, 0.13-0.28; P Յ .005). Among placebo-treated patients, 27.5% had a clinically meaningful worsening (Ն5-point decrease) in SF-36 PCS scores during the 2 years. Walking speed declined by 21.8% in these patients after 2 years, but only by 5.4% in those without worsening of SF-36 PCS scores. CONCLUSIONS AND RELEVANCE In patients with MS, walking speed measured using the T25-FW correlated with SF-36 PCS scores such that a decline in walking speed of 20% to 25% corresponded to a clinically meaningful worsening of SF-36 PCS scores. A 20% to 25% decline in walking speed may be a clinically meaningful threshold for defining worsening using the T25-FW in MS clinical trials and for monitoring patients in clinical settings.

Correlation of Changes in Gait Parameters, With Phenotype, Outcome Measures, and Electrodiagnostic Abnormalities in a Patient With Anti-MAG Neuropathy After Exacerbation and Improvement

“…For reference, a 20%-25% decline in walking speed has correlated with clinical decline in multiple sclerosis. 9 Similar trends were noted in studies of patients with diabetic neuropathy compared with control subjects. 8 The changes in spatiotemporal gait parameters correlated with changes in INCAT, MRC scores, and grip strength, but seemed to be more sensitive as they detected greater improvement, to above baseline values at 3 months.…”

Nonsignificant Associations Between Measures of Inhibitory Control and Walking While Thinking in Persons With Multiple Sclerosis

“…The mean T25FW speed for persons with MS was faster than that of a large trial of ambulatory persons with a broad range of MS disability 31. …”

Prolonged-release fampridine in multiple sclerosis: Improved ambulation effected by changes in walking pattern

“…This difference in effect sizes may explain the absence of a significant change in the related patient-based outcome measure of walking function. In the previous trials, the 12-item WS was used to show that the effects of PR-fampridine were clinically meaningful 6,7,10,11 . In the present study, clinical relevance of the observed improvements was demonstrated by the accelerometer data, showing for the first time that treatment with PR-fampridine enhances physical activity in everyday life in responders.…”