Psychometric comparison and score conversion between World Health Organization Disability Assessment Schedule 2.0 and activities of daily living scales in community-dwelling older adults.

Purpose: To compare the performance of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) with activities of daily living (ADL) scales for disability assessment and to explore the score conversion between these two measures in a community-dwelling geriatric population.

Methods: Data were drawn from the observational cohort study, the Beijing Longitudinal Disability Survey in Community Elderly, including 2170 community-dwelling adults aged ≥ 65 years. The 12-item WHODAS 2.0, ADL scales, and other corresponding measurements (mobility, cognition, depression, pain, nutrition, frailty, and sarcopenia) were evaluated face-to-face by well-trained assessors. Receiver operating characteristic (ROC) curve analysis was used to assess the accuracy of discriminating participants with ADL disability. Spearman's correlation coefficients were calculated to evaluate the associations between WHODAS 2.0, ADL scales, and other geriatric assessment tools. Equipercentile equating was performed to develop a conversion table between the WHODAS 2.0 and ADL scales.

Results: Among 2170 community-dwelling older adults, the mean (SD) age was 74.1 (7.2) years, and 867 (40.0%) were male. Using the ADL scales, 1660 participants (76.5%) were defined as independent and 510 (23.5%) as dependent. Our results found an agreement between WHODAS 2.0 and ADL in categorizing older adults with disability. WHODAS 2.0 had a sensitivity of 95.1% and specificity of 77.3% in detecting disabled versus non-disabled older adults, with an area under the ROC curve of 0.963. WHODAS 2.0 also presents strong correlations with ADL scales and other geriatric assessment tools. In addition, a conversion table between WHODAS 2.0 and ADL scores was built with high precision.

Conclusion: WHODAS 2.0 demonstrates good discriminative ability for ADL disability and correlates strongly with various geriatric assessments, supporting that it is an applicable, sensitive, and comprehensive measure for disability assessment in community-dwelling older adults. The conversion between the WHODAS 2.0 and ADL scales allows for the comparison and synthesis of scores across studies and offers clinicians valuable references when interpreting results from different disability scales.