Performance of Upper Limb module for Duchenne muscular dystrophy

Abstract

AIM To report the differences between Performance of Upper Limb (PUL) versions 1.2 and 2.0, compare the measurement ability of the two versions, and compare their longitudinal performance in Duchenne muscular dystrophy. METHOD Rasch analysis was performed on the dual data from three centres to confirm whether the two scales measure the same construct. Change scores in natural history for the different domains were compared for the two versions. RESULTS Rasch analysis demonstrated that both versions measure the same construct and that the PUL 2.0 was a better fit to the construct of motor performance and better able to detect change at 12 months in all levels of ability than the PUL 1.2. This was also true when change scores were reviewed over 2 years. INTERPRETATION Our results confirm that the PUL 1.2 and 2.0 versions detect change in all domains over 2 years. They also demonstrate that simplifying the original scoring of the PUL 1.2 for the revised PUL 2.0 maintains the validity of the construct and enhances the scale measurement qualities.