Responsiveness of the Motor Function Measure in Neuromuscular Diseases

Abstract Vuillerot C, Payan C, Girardot F, Fermanian J, Iwaz J, Bérard C, Ecochard R, the MFM Study Group. Responsiveness of the Motor Function Measure in neuromuscular diseases. Objectives To study the responsiveness (sensitivity to change) of the Motor Function Measure (MFM) in detecting change in neuromuscular disease patients with the intent of using this measure in future clinical trials. Design Prospective cohort observational study. Setting Inpatient and outpatient facilities for follow-up and treatment of neuromuscular diseases. Participants Patients (N=152) with various neuromuscular diseases aged 6 to 60 years. Interventions Not applicable. Main Outcome Measure(s) We used the MFM total score and its 3 subscores on 2 measurements grossly 1 year apart. The physicians and the patients (or proxy) were asked to provide their perceived change in functional status since the first MFM. These changes were expressed in 3 outcomes: deterioration, stability, or improvement. Results The overall 12-month-standardized mean change of the total score mean ± SD annual total score change was −2.4±5.5 points ( P