Reliability and validity of the 4-meter walk test in patients with multiple sclerosis.

ABSTRACT

BACKGROUND: Walking speed is considered a vital sign of health and better functional outcomes. It is important to assess walking speed both for disease monitoring and before starting rehabilitation. The aim of this study was to examine the reliability, validity, minimal detectable change, and the ideal cutoff time for differentiating patients with multiple sclerosis (PwMS) who fall from PwMS who do not. METHODS: This study included 43 PwMS (26 female and 17 male) and 36 healthy controls (23 female and 13 male). The 4-meter walk test (4-MWT) was conducted with the 10-meter walk test (10-MWT), timed up and go (TUG) test, dynamic gait index (DGI), timed 25-foot walk (T25-FW), multiple sclerosis walking scale-12 (MSWS-12), and the expanded disability status scale (EDSS). RESULTS: Excellent test-retest reliability (ICC = 0.971) was found for the 4-MWT. The SEM value was 0.38 and MDC value was 1.05. The correlations with 4-MWT, 10-MWT, TUG, DGI, T25-FW, MSWS-12, and EDSS were found to be statistically significant (p < 0.001). PwMS had longer 4-MWT times than healthy controls, and PwMS fallers had longer 4-MWT times than non-fallers with PwMS (r between 0.668 and -0.858; p < 0.05 for all). In order to distinguish fallers from non-fallers with PwMS, a 4-MWT cutoff time of 4.14 s was shown to be optimal. CONCLUSION: The 4-MWT was found to be valid and reliable for PwMS. It is concluded that the 4-MWT is a feasible assessment method for clinical and methodological studies of PwMS with mild to moderate disability.