Agreement of the 12-item World Health Organization Disability Assessment Schedule (WHODAS) 2.0 in parents and youth with physical illness living in Canada

Abstract

Purpose

This study modelled the factor structure and tested for measurement invariance between youth and parent reports on the 12-item World Health Organization Disability Assessment Schedule (WHODAS) 2.0; estimated agreement between informants; and, examined moderators of youth-parent discrepancies.

Materials and Methods

Data come from the baseline wave of the Multimorbidity in Youth across the Life-course study (n = 117). Multiple-group confirmatory factor analysis was used to test for measurement invariance and Wilcoxon signed-rank tests compared informant scores. Intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement plots were used to examine the youth-parent agreement.

Results

The WHODAS 2.0 demonstrated measurement invariance [χ² = 221.8(136), p < 0.01; RMSEA = 0.073 (0.055, 0.091); CFI = 0.962; and, SRMR = 0.078]. Youth typically reported more disability compared to parent proxies, with the exception of item Q5 (emotional). The agreement was low (ICC = 0.08–0.53). Youth sex moderated informant agreement such that more consistent agreement was seen for female youth (β = 0.54, p < .01) compared to male youth (β = 0.11, p = .29).

Conclusions

Youth and their parents interpret the construct of disability, as measured by the 12-item WHODAS 2.0, similarly. Thus, informant differences represent real differences that are not a consequence of error. Low parent-youth agreement reinforces the need for collecting multiple perspectives in the pediatric setting, especially for male youth.

Implications for rehabilitation

• The WHODAS 2.0 is one of the most widely used measures of disability and functioning.

• Measurement invariance of the WHODAS 2.0 suggests that youth and parents interpret the construct of disability similarly.

• Parent-youth agreement was low and youth typically report more disability compared to parent proxies.

• More consistent agreement with parents was found for female youth compared to male youth.

Keywords:

• Adolescent/child
• chronic disease
• measurement
• reliability
• validity

Acknowledgements

The authors gratefully acknowledge the children, parents, and health professionals and their staff at McMaster Children’s Hospital without whose participation this study would not have been possible. We especially thank Jessica Zelman, Robyn Wojicki, and Charlene Attard for coordinating the study and assisting with data collection. This study was funded by a grant awarded to MAF by the Canadian Institutes of Health Research (PJT-148602). MAF holds the Canada Research Chair in Youth Mental Health and is the recipient of an Early Researcher Award from the Ontario Ministry of Research, Innovation and Science.

Disclosure statement

None of the authors has a conflict of interest to disclose.

Data availability statement

The data that support the findings of this study may be available on request from the corresponding author, MAF. The data are not publicly available due to their containing information that could compromise the privacy of research participants. Ethical approval was not obtained to share data publicly.