The responsiveness of Motor Function Measure-Chinese version (MFM 32-CN) in children and adolescents with Duchenne muscular dystrophy
Abstract Objectives: This study aims to examine the responsiveness of the Motor Function Measure Chinese version (MFM 32-CN) in children and adolescents with Duchene muscular dystrophy (DMD). Methods: 148 participants were consecutively recruited. Assessments, including the Brooke and Vignos scales, the MFM 32-CN and the Clinical Global Impression-Severity scale (CGIS), were performed during their first visit (T1) and at six- (T2) and twelve-month (T3) follow up time points. The relationship between MFM scores and age was studied. The standardized response means (SRMs) were used to determine the instrument’s responsiveness. Results: It was found that changes in MFM total score showed significant deterioration over time: -4.46±3.10 points per six months and -9.78±4.79 points per year. The MFM total score (SRM: 1.30 to 3.76), D1 (SRM: 1.10 to 3.20) and D2 (SRM: 0.94 to 2.31) subtotal scores demonstrated substantially high responsiveness at both T2 and T3. D1 presented the highest responsiveness (SRM: 1.25 to 3.20) among patients with ambulation and within a mild to moderate range of severity. By contrast, D2 showed the highest responsiveness (SRM: 1.43 to 2.31) in the non-ambulant and severe groups. The responsiveness of D3 was not satisfactory (SRM: 0.23 to 0.56) in the general sample, but high (SRM: 0.82 to 1.86) in non-ambulant and severe patients. Conclusions: Motor function of individuals with DMD deteriorated rapidly and dramatically during childhood and early adolescence. The MFM-32 Chinese version is a highly responsive tool in detecting changes in motor function over time in children and adolescents with DMD.