Are Changes in Gait and Balance Across the Disease Step Rating Scale in Multiple Sclerosis Statistically Significant and Clinically Meaningful?

Katrina L. Williams, Nancy L. Low Choy, Sandra G. Brauer

To explore differences in gait endurance, speed and standing balance in people with Multiple Sclerosis (MS) across the Disease Step Rating Scale (DSRS), and to determine if differences are statistically significant and clinically meaningful. Observational Study. 222 community dwelling people with MS (Mean age 48 ± 12 years; 32% male) INTERVENTION: Not applicable: Main Outcome Measures: Participants were categorised using the DSRS. Demographics and clinical measures of gait endurance (6 minute walk test - 6MWT), gait speed (10 meter walk test - 10MWT; 25foot walk test - 25FWT) and balance (Berg Balance Scale - BBS) were recorded in one session. Differences in these parameters across categories of the DSRS were explored and clinically meaningful differences identified. The 6MWT showed a greater number of significant differences across adjacent Disease Steps in those with less disability (p < 0.001), while the 10MWT and 25FWT demonstrated more significant changes in those with greater disability (p < 0.001). The BBS demonstrated significant differences across the span of the DSRS categories (p < 0.001). Differences in gait and balance between adjacent DSRS categories met most previously established levels of minimally detectable change and all minimally important change scores. Out findings support the DSRS is an observational tool that can be used by health professionals to categorise people with MS, with the categories reflective of statistically significant and clinically meaningful differences in gait and balance performance.