Validation of the World Health Organization Disability Assessment Schedule 2.0 Among People With Disabilities Using Rasch Analysis in WINSTEPS

AIMS/BACKGROUND: The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is extensively used internationally for assessing disabilities across diverse cultures and health conditions; however, psychometric validation of its Arabic version remains scarce. This study aimed to evaluate the psychometric properties regarding the Arabic WHODAS 2.0 using Rasch analysis, providing the first validation evidence of reliability, validity, dimensionality, and item functioning among individuals with disabilities in Arabic-speaking populations. METHODS: This cross-sectional study included 486 Arabic-speaking participants. Rasch analysis was performed using WINSTEPS software to assess item fit, item and person reliability, unidimensionality, separation indices, differential item functioning (DIF), and category functioning. RESULTS: The Arabic WHODAS 2.0 showed strong person (0.80) and item (0.99) reliability, with adequate item-person targeting. Most items fit the Rasch model, except for World Health Organization Disability Assessment Schedule 5 (WHODAS5), which displayed misfit and disorder thresholds. Principal component analysis supported unidimensionality (53.4% variance explained), and no significant DIF was detected across the demographic groups. CONCLUSION: The Arabic version of the WHODAS 2.0 is a reliable and valid tool for assessing disability in Arabic-speaking populations. Overall, it demonstrated strong psychometric properties, although the WHODAS5 requires revision. This scale is suitable for clinical and research use, with recommendations for further qualitative validation and longitudinal testing.