Understanding the relationship between the 32-item motor function measure and daily activities from an individual with spinal muscular atrophy and their caregivers\u2019 perspective: a two-part study

Tina Duong,Aurelie Barriere,Nicole Gusset,Jessica Flynn,Angela De Martini,Hannah Staunton,Jessica Braid,Jill Jarecki,Rob Arbuckle,Mencia De Lemus,Carole Vuillerot,Ria Broekgaarden,Lida Yang,Sharan Randhawa,Sonia Reif,Rosangel Cruz,Fani Petridis,Johannes Reithinger

doi:10.1186/s12883-021-02166-z

Abstract

BackgroundThe 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.MethodsIn-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.ResultsQualitative 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.ConclusionThis 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.

Highlights

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)
Overview of interview resources relating to the MFM32 The MFM32 measure is comprised of 32 items that assess a range of different motor functional abilities across three functional domains: standing and transfers (D1: 13 items), axial and proximal motor function (D2: 12 items) and distal motor function (D3: 7 items) [10]
The most frequently reported activities of daily living (ADL) considered to be 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

Summary

Introduction

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). Spinal muscular atrophy (SMA) is a rare neurodegenerative disease caused by a loss of function, mutation or deletion of the survival of motor neuron 1 gene (SMN1). Individuals with Type 2 SMA are able to sit unsupported, though they are typically unable to stand or walk independently; whereas, individuals with Type 3 SMA are able to stand and walk independently, though these abilities may be lost as the disease progresses [2, 4] Despite this distinct subtype classification, there is often a high degree of within-group variation and classification is not a strict predictor of disease progression. As well as the advent of approved disease-modifying therapies, classification of SMA by subtypes has evolved to focus on the functional status of the individuals (nonsitters, sitters/standers, walkers) [5, 6]

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Conclusion