Psychometric properties and informant agreement of the WHODAS 2.0 in youth with mental disorder.

Objective: This study examined psychometric properties, parent-youth agreement, and factors associated with agreement on the 12-item and 36-item versions of the World Health Organization Disability Assessment Schedule (WHODAS) 2.0. Methods: Data come from a clinical sample of 56 youth, aged 14-17 years, receiving mental health care at a pediatric hospital. Correlations between the WHODAS 2.0, KIDSCREEN-27, and demographic variables were used to assess validity. Internal consistency was measured using ordinal alpha. The Bland-Altman method and intraclass correlation coefficients (ICC) were used to assess parent-youth agreement. Logistic regression examined factors associated with disagreement > 0.5 standard deviation. Results: For both parent and youth, correlations were low to moderate in exploring convergent (τ= -0.42 to 0.01) and divergent validity (τ/r = -0.12 to 0.32). Internal consistency was adequate (α > 0.7). Parent WHODAS 2.0 scores were significantly lower than youth scores and Bland-Altman plots revealed poor parent-youth agreement (ICC = -0.04 to 0.33). Lower household income was associated with lower odds of disagreement on the 35-item WHODAS 2.0 (OR= 0.28, 95% CI= 0.08-0.99), and older youth age was associated with lower odds of disagreement on the 12-item WHODAS 2.0 (OR= 0.40, 95% CI= 0.19-0.84). Conclusion: The psychometric properties of both WHODAS 2.0 versions were similar, so the abbreviated version may be sufficient to measure functional impairment in a clinical context. Additional research is needed to better understand the factors that influence discrepancies between informants and the implications for care. However, reports from both youth and parents appear valuable in understanding functional impairment.