Investigating psychometric properties of the arm activity measure – Thai version (ArmA-TH) sub?scales using the Rasch model

Abstract Background This study investigated the ArmA-TH sub-scale measurement properties based on item response theory using Rasch model. Methods Patients with upper limb hemiplegia resulting from cerebrovascular and other brain disorders were asked to complete questionnaire. analysis was performed test how well passive active function sub-scales fit model by investigating unidimensionality, category functioning, reliability of person item, differential functioning (DIF) for age, sex, education. Results Participants had stroke or acquired injury (n = 185), majority men (126, 68.1 %), a mean age 55 (SD 22). Most patients (91, 49.2 %) graduated elementary/primary school. For scale, all items acceptable statistics. The scale’s unidimensionality local independence supported. acceptable. A disordered threshold found five items, none indicated DIF. one misfit three locally dependent. good. No showed All thresholds, data fitted better after rescoring. Conclusions Both valid reliable. thresholds should be further investigated.