Are novel outcome measures for Charcot–Marie–Tooth disease sensitive to change? The 6-minute walk test and StepWatch™ Activity Monitor in a 12-month longitudinal study.

• CMT slowly progress over time, appropriate outcome measures are needed to detect it. • StepWatch™ Activity Monitor reflect real-life function in CMT patients. • StepWatch™ Activity Monitor showed to be able to detect progression over time. Charcot–Marie–Tooth (CMT) is the most common inherited neuropathy, yet has no available pharmacological therapy. Past pharmacotherapy trials failed to provide positive results, possibly due to a poor choice of outcome measures. We previously performed a study in which we validated the 6-minute walk test and StepWatch™ Activity Monitor in CMT. The aim of the current study was to determine if these outcome measures are sensitive to change over a 12-month period. In this longitudinal multicenter study, 149 out of 169 initially enrolled patients were re-evaluated after 12 months using the 6-minute walk test, StepWatch™ Activity Monitor and other outcome measures commonly adopted in CMT disease. Statistical analysis showed a worsening of the CMT-Neuropathy Score (p < 0.05), strength of distal muscles measured by myometry (p < 0.05) and StepWatch™ Activity Monitor outputs (p < 0.05). The 10 meter walking test (p > 0.05), muscular strength as detected by clinical evaluation (p > 0.05), 6-minute walk test (p > 0.05), pain (p > 0.05) and quality of life (p > 0.05) showed no change. In the current study, patients showed clinical worsening over 12 months, confirmed by a reduction of activity as detected by StepWatch™ Activity Monitor. The 6-minute walk test failed to detect change. [ABSTRACT FROM AUTHOR]