P.2.5 Performance of Upper Limb Scale for use in Duchenne muscular dystrophy – An iterative process to establish its suitability for clinical trials

In 2012 a group of international physiotherapists specializing in neuromuscular assessments devised a ClinRO to assess upper limb performance (PUL) for use in Duchenne muscular dystrophy (DMD). An exploratory Rasch analysis helped establish version one of the PUL although it was recognized at the time further analysis was required in a larger subset to confirm these preliminary findings and potentially remove redundant items. The aim of this study is to repeat the analysis in a larger cohort, again on an international level. Over 300 assessments from both ambulant and non-ambulant individuals with DMD were analysed using RUMM2030 from Italy, UK, Belgium and USA. The age range was from 4 to 25 and data were examined for psychometric properties including clinical meaning, targeting, response categories, fit, reliability, dependency, stability and interval level measurement. Following analysis each item was reviewed both for scoring options and redundancy and a revised scale produced (Version two). Psychometric analysis confirmed the preliminary findings and also highlighted areas where some items were potentially redundant. A shortened/ revised scale was created by the expert group. This iterative process of ClinRO development is essential to establish a robust measure. Further work needs to be conducted on reliability and responsiveness to confirm the PUL’s suitability for inclusion in clinical trials.