Design and Validation of a Clinical Outcome Measure for Adolescents and Adult Patients with Spinal Muscular Atrophy: SMA Life Study Protocol

Abstract

Introduction The objective of this study is to develop a clinical tool for the evaluation and follow-up of adolescent and adult patients with 5q spinal muscular atrophy (SMA) and to design its validation. Methods This prospective, non-interventional study will be carried out at five centres in Spain and will include patients aged 16 years or older with a confirmed diagnosis of 5q SMA (biallelic mutation of the survival motor neuron 1 [ SMN1 ] gene). A panel of experts made up of neurologists, physiatrists and Spanish patients’ association (FundAME), participated in the design of the clinical tool. Physicians will administer the tool at three time points (baseline, 12 months and 24 months). Additionally, data from other questionnaires and scales will be collected. Once recruitment is achieved, an interim statistical analysis will be performed to assess its psychometric properties by applying Rasch analysis and classical statistical tests. Results The tool will consist of up to 53 items to assess functional status from a clinical perspective in seven key dimensions (bulbar, respiratory, axial, lower, upper, fatigability and other symptoms), which will be collected together with objective clinical measures (body mass index, forced vital capacity, pinch strength and 6-minute walk test). Conclusions The validation of this tool will facilitate the clinical evaluation of adult and adolescent patients with SMA and the quantification of their response to new treatments in both clinical practice and research.