Development of a New Daily Activities Scale for the Affected Hand after Stroke

Objectives There are few scales that reflect the function of the stroke-affected arm as it relates to the performance of daily activities while also indicating the difficulty of scale items. In this study, we developed the Activities Specific Upper-extremity Hemiparesis Scale (ASUHS) to evaluate daily activities performable by the affected arm after stroke. We also clarified the validity, reliability, and item difficulty of the scale. Methods The participants were 145 patients with stroke who were consecutively admitted to a convalescent rehabilitation ward. The unidimensionality of ASUHS was assessed by principal component analysis. Analyses of item discrimination and content validity were conducted to assess the overall validity. Reliability was evaluated by assessing internal consistency and inter-rater reliability. Item difficulties were determined by Rasch analysis. Results Unidimensionality, high discrimination, and good content validity were shown for all items. ASUHS consists of a dominant hand scale and non-dominant hand scale. Both scales showed good internal consistency (Cronbach's α coefficient = 0.99) and substantial inter-rater reliability (Cohen's Kappa coefficient = 0.74 and 0.75, respectively). Item difficulty was determined as being in the range -8.71 to +5.18 logit. Conclusions This study suggested good validity and reliability of ASUHS. Furthermore, because the item difficulties of daily activities performed by the affected arm were clarified, therapists can use ASUHS to identify the process that should be the next focus for training. Consequently, therapists may be able to train patients in daily activities that match the affected arm's ability step by step rather than determining training activities empirically.