Validation of the 2-Minute Walk Test with the 6-Minute Walk Test and Other Functional Measures in Persons with Multiple Sclerosis.

Abstract

Persons with multiple sclerosis (MS) commonly have difficulty walking. The 6-Minute Walk Test (6MWT) assesses functional capacity but may be considered burdensome for persons with MS, especially those with higher disability levels. The 2-Minute Walk Test (2MWT) may be an alternative measure to the 6MWT. The purpose of this study was to investigate the validity of the 2MWT in persons with MS. Twenty-eight ambulatory persons with MS aged 18 to 64 years participated in this cross-sectional study. Participants completed five measures of walking performance (2MWT, 6MWT, usual and fast gait speed, and Timed Up and Go test) and two functional measures (Berg Balance Scale and five-times sit-to-stand test) during a testing session. Participants were classified into two subgroups based on Disease Steps scale classification. The 2MWT was significantly correlated with the 6MWT (r = 0.947), usual gait speed (r = 0.920), fast gait speed (r = 0.942), the Timed Up and Go test (r = -0.911), and other functional measures. The 2MWT explained 89% of the variance seen during the 6MWT. The distances completed on the 2MWT and 6MWT accurately distinguished the subgroups. This study demonstrated good construct and discriminant validity of the 2MWT in persons with MS, providing an efficient and practical alternative to the 6MWT. Validation of the 2MWT with other functional measures further supports these findings.