Factorial Validity of the 32-Item World Health Organization Disability Assessment Schedule 2.0 in Persons With Stroke.

Background and purpose: The World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) is a well-established tool for assessing disability. However, diverse factor structures complicate its interpretation, necessitating further validation. This study examined the factorial validity of the 32-item WHODAS 2.0 in persons with stroke using 1-factor, 6-factor, and 2-level hierarchical structures.

Methods: A cross-sectional design was used with data from 1343 persons with stroke in the Taiwan Databank of Persons with Disabilities. Confirmatory factor analysis (CFA) was used to determine the valid structure of the 32-item WHODAS 2.0.

Results: The 1-factor structure exhibited poor model fits, while the 6-factor and the overall 2-level hierarchical structure had acceptable model fits. However, the relationships between domains and overall score of the 2-level structure yielded poor fits. Excellent internal consistencies (Cronbach's α ≥ 0.90) were obtained for the 6 domain scores and the overall score.

Discussion and conclusions: Our results revealed poor model fit for the 1-factor model, whereas the 6-factor structure and the overall 2-level hierarchical structure were both acceptable. However, the relationships between domains and the overall score within the 2-level structure were poor. The 6-factor model is preferable due to its better fit and alignment with WHODAS 2.0's design to assess multiple life perspectives. The 6-domain structure appears the most robust for persons with stroke. Thus, the 6 domain scores of the 32-item WHODAS 2.0 are recommended.