Psychometric Properties of the Disability Acceptance Scale in Individuals with Intellectual Disabilities

This study aimed to verify the psychological properties of the Disability Acceptance Scale (DAS) for individuals with intellectual disabilities using Rasch analysis. I extracted self-reported data from 216 individuals with intellectual disabilities from the Korea Panel Survey on Employment of Persons with Disabilities and performed Rasch analysis. Consequently, items 1, 3, and 7 of the original 12 items were removed as they did not meet the criteria for item fit. Subsequently, the final nine items were re-analyzed. The results revealed that all items demonstrated appropriate item fit; furthermore, item difficulty was distributed within a range capable of measuring various levels of disability acceptance. Moreover, the rating scale functioned sequentially in its response categories, and both subject (0.83) and item reliability (0.96) met the recommended standards. These results suggest that the 9-item DAS can reliably and validly evaluate the level of disability acceptance among individuals with intellectual disabilities. This study verified the metrological characteristics of the DAS for people with intellectual disabilities based on the Rasch model. The DAS can be used as an evidence-based tool for evaluating disability acceptance in education, rehabilitation, psychological counseling, and vocational rehabilitation.