Functional outcome measures in young, steroid-naive boys with Duchenne muscular dystrophy

The purpose of this study was to quantitate motor performance in 196 genetically confirmed steroid-naive boys with Duchenne muscular dystrophy (DMD), to evaluate the test-retest reliability of measures of motor performance in young DMD boys, and to assess correlations among the different functional outcomes including timed tests. Boys aged 4-7 years were recruited in the FOR-DMD study, a comparative effectiveness study of different steroid regimens in DMD. Eligible boys had to be able to rise from the floor independently and to perform pulmonary function testing consistently. The boys were evaluated with standardized assessments at the screening and baseline visits at 32 sites in 5 countries (US, UK, Canada, Italy, Germany). Assessments included timed rise from floor, timed 10 m walk/run, six-minute walk distance, North Star Ambulatory Assessment (NSAA) and forced vital capacity (FVC). Mean age at baseline was 5.9 years (range 4.1-8.1 years). Test-retest reliability was high for functional assessments, regardless of time lag between assessments (up to 90 days) and for the majority of age groups. Correlations were strong among the functional measures and timed tests, less so with FVC. Physiotherapy measures are reliable in a young, steroid-naive population and rise from floor velocity appears to be a sensitive measure of strength in this population. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Automated summary

The purpose of this study was to quantify motor performance in genetically confirmed steroid-naive boys with Duchenne muscular dystrophy (DMD), evaluate the test-retest reliability of measures of motor performance in young DMD boys, and assess correlations among different functional outcomes. The study found that physiotherapy measures are reliable in a young, steroid-naive population and rise from floor velocity appears to be a sensitive measure of strength in this population.