Understanding the relationship between the 32-item motor function measure and daily activities from an individual with spinal muscular atrophy and their caregivers' perspective: a two-part study.

BACKGROUND: The 32-item Motor Function Measure (MFM32) is a clinician-reported outcome measure used to assess the functional abilities of individuals with neuromuscular diseases, including those with spinal muscular atrophy (SMA). This two-part study explored the relationship between the functional abilities assessed in the MFM32 and activities of daily living (ADLs) from the perspective of individuals with Type 2 and Type 3 (non-ambulant and ambulant) SMA and their caregivers through qualitative interviews and a quantitative online survey. METHODS: In-depth, semi-structured, qualitative interviews were conducted with individuals with SMA and caregivers from the US. Subsequently, a quantitative online survey was completed by individuals with SMA or their caregivers from France, Germany, Italy, Poland, Spain, Canada, the United States (US) and the UK. In both parts of the study, participants were asked to describe the ADLs considered to be related to the functional abilities assessed in the MFM32. Results from the qualitative interviews informed the content of the quantitative online survey. RESULTS: Qualitative interviews were conducted with 15 adult participants, and 217 participants completed the quantitative online survey. From the qualitative interviews, all of the functional abilities assessed in the patient-friendly MFM32 were deemed as related to one or more ADL. The specific ADLs that participants considered related to the patient-friendly MFM32 items could be grouped into 10 key ADL domains: dressing, mobility/transferring, self-care, self-feeding, reaching, picking up and holding objects, physical activity, writing and technology use, social contact/engagement, toileting and performing work/school activities. These results were confirmed by the quantitative online survey whereby the ADLs reported to be related to each patient-friendly MFM32 item were consistent and could be grouped into the same 10 ADL domains. CONCLUSION: This study provides in-depth evidence from the patient/caregiver perspective supporting the relevance of the patient-friendly MFM32 items to the ADLs of individuals with Type 2 and Type 3 SMA.

A Patient-Centered Evaluation of Meaningful Change on the 32-Item Motor Function Measure in Spinal Muscular Atrophy Using Qualitative and Quantitative Data.

The 32-item Motor Function Measure (MFM32) is an assessment of motor function used to evaluate fine and gross motor ability in patients with neuromuscular disorders, including spinal muscular atrophy (SMA). Reliability and validity of the MFM32 have been documented in individuals with SMA. Through semi-structured qualitative interviews (N = 40) and an online survey in eight countries (N = 217) with individuals with Types 2 and 3 SMA aged 2-59 years old and caregivers, the meaning of changes on a patient-friendly version of the MFM32 was explored. In an independent analysis of clinical trial data, anchor- and distribution-based analyses were conducted in a sample of individuals with Type 2 and non-ambulant Type 3 SMA to estimate patient-centered quantitative MFM32 meaningful change thresholds. The results from this study demonstrate that, based on patient and caregiver insights, maintaining functional ability as assessed by a patient-friendly version of the MFM32 is an important outcome. Quantitative analyses using multiple anchors (median age range of 5-8 years old across anchor groups) indicated that an ~3-point improvement in MFM32 total score represents meaningful change at the individual patient level. Overall, the qualitative and quantitative findings from this study support the importance of examining a range of meaningful change thresholds on the MFM32 including ≥0 points change reflecting stabilization or improvement and ≥3 points change reflecting a higher threshold of improvement. Future research is needed to explore quantitative differences in meaningful change on the MFM32 based on age and functional subgroups.

Validity and Reliability of the 32-Item Motor Function Measure in 2- to 5-Year-Olds with Neuromuscular Disorders and 2- to 25-Year-Olds with Spinal Muscular Atrophy.

INTRODUCTION: To investigate the validity and reliability of the 32-item Motor Function Measure (MFM32) in individuals with neuromuscular disorders (NMD), including spinal muscular atrophy (SMA), aged 2-5 years, and in non-ambulant individuals with Types 2 or 3 SMA, aged 2-25 years. METHODS: Test-retest reliability (intraclass correlation coefficient [ICC]), internal consistency (Cronbach's alpha [α]), convergent validity (Spearman rank-order correlations), and known-groups validity (analysis of covariance comparing groups defined by the Clinical Global Impression of Severity [CGI-S] scale and Vignos grade) were calculated. The analysis was performed on a dataset provided by Hospices Civils De Lyon, extracted from the multinational MFM32 database. A total of 165 individuals were included in the analyses, of whom 84 were in the NMD group (aged 2-5 years) and 81 were in the SMA group (aged 2-25 years). RESULTS: Strong evidence of test-retest reliability (ICC: 2- to 5-years' population = 0.94-0.95; 2- to 25-years' population = 0.97), internal consistency (Cronbach's α: 2- to 5-years' population = 0.96; 2- to 25-years' population = 0.95), convergent validity (2- to 5-years' population: CGI-S rho = - 0.84, Vignos grade rho = - 0.79; 2- to 25-years' population: CGI-S rho = - 0.49), and known-groups validity (all P < 0.001) were demonstrated. CONCLUSIONS: These analyses provide supportive evidence of the validity and reliability of the MFM32 in younger individuals with NMDs, aged 2-5 years, and in non-ambulant individuals with Types 2 or 3 SMA, aged 2-25 years, supporting the use of the MFM32 across a wide age range.