Measurement invariance of the 12-item self-administered World Health Organization Disability Assessment Schedule (WHODAS) 2.0 across early and late adolescents in Canada

PURPOSE

This study examined whether the 12-item self-administered World Health Organization Disability Assessment Schedule (WHODAS) 2.0 demonstrated measurement invariance between young adolescents aged 10-16 years with a physical illness and older adolescents aged 15-19 years from the general population.

MATERIALS AND METHODS

Young adolescent data come from the baseline wave of the Multimorbidity in Youth across the Life-course study (n = 117) and older adolescent data come from the Canadian Community Health Survey-Mental Health (n = 1851). Multiple-group confirmatory factor analysis was used to test measurement invariance. WHODAS 2.0 scores were compared across morbidity subgroups using multiple regression.

RESULTS

Measurement invariance of the WHODAS 2.0 was demonstrated: (χ2=635.2(144), p<.001; RMSEA = 0.059 (0.054, 0.064); CFI = 0.967; TLI = 0.970; and, SRMR = 0.068). Adjusting for data source, sex, race, immigrant status, and household income, WHODAS 2.0 scores were associated with morbidity status in a dose-response manner: physical illness only (B = 1.50, p<.001), mental illness only (B = 2.92, p<.001), and physical-mental comorbidity (B = 4.44, p<.001).

CONCLUSIONS

Measurement invariance of the WHODAS 2.0 suggests that young adolescents interpret the items and disability construct similarly to older adolescents - a group that previously demonstrated measurement invariance with an adult sample. The 12-item self-administered WHODAS 2.0 may be used to measure disability across the life-course. IMPLICATIONS FOR REHABILITATIONThe 12-item self-administered WHODAS 2.0 is one of the most widely used measures of disability and functioning.Measurement invariance of the WHODAS 2.0 suggests that young adolescents interpret the items and disability construct similarly to older adolescents and adults in Canada.Researchers and health professionals can be confident that differences in 12-item self-administered WHODAS 2.0 scores are real and meaningful.The 12-item self-administered WHODAS 2.0 may be used to measure disability across the life-course.

Validating the 12-item proxy-administered World Health Organization Disability Assessment Schedule (WHODAS) 2.0 in young children with chronic physical illness in Canada

PURPOSE

This study investigated the psychometric properties of the 12-item proxy-administered World Health Organization Disability Assessment Schedule (WHODAS) 2.0 in young children with chronic physical illness in Canada.

MATERIALS AND METHODS

Data come from the Multimorbidity in Youth across the Life-course, a longitudinal study of Canadian youth with physical illnesses (n = 263). Baseline parent-reported data from children (2-9 years, n = 143) and adolescents (10-16 years, n = 117) were analyzed. Wilcoxon's tests examined differences in WHODAS 2.0 scores between subgroups. Internal consistency was estimated, and confirmatory factor analysis modeled the WHODAS 2.0 factor structure. Regression modeling examined if the WHODAS 2.0 could discriminate between children with vs. without mental comorbidity.

RESULTS

Differences were found between children and adolescents regarding self-care and getting along, and for the item on emotional affect. Inter-item correlations were similar between subgroups and internal consistency was strong for children (α = 0.90) and adolescents (α = 0.93). The factor structure of the WHODAS 2.0 was confirmed; parameter estimates were similar between subgroups. The association between mental comorbidity and disability did not differ by age - comorbidity was associated with greater disability (β = 5.87, p < 0.01).

CONCLUSIONS

The 12-item proxy-administered WHODAS 2.0 appears valid and reliable in young children with physical illness and can be used in this population.Implications for rehabilitationThe 12-item proxy-administered WHODAS 2.0 has acceptable inter-item correlations and internal consistency in young Canadian children with chronic physical illness, and its factor structure is consistent with previous reportsExpansion of its use in measuring disability in young children provides the opportunity to use the WHODAS 2.0 across the life-course, facilitating the interpretation of changes in disability over time or in response to treatmentAdditional research is needed to determine responsiveness to change and the minimal clinically important difference of the WHODAS 2.0 in this population.

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

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 rehabilitationThe 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.

Investigating executive functions in youth with OCD and hoarding symptoms

Executive functions (EF) deficits are hypothesized to be a core contributor to hoarding symptoms. EF have been studied in adult hoarding populations, but studies in youth are lacking. The current study compared multiple EF subdomains between youth with obsessive-compulsive disorder (OCD) and youth with OCD and hoarding symptoms. Forty youth (8-18 years old) with a primary diagnosis of OCD were recruited. Participants were divided by hoarding severity on the Child Saving Inventory (CSI) into either the "hoarding group" (upper 33.3%) or the "low-hoarding group" (lower 66.7%). Groups were compared on EF tasks of cognitive flexibility, decision-making, and inhibitory control. Youth in the hoarding group exhibited significantly higher cognitive flexibility and lowered perseveration than the low-hoarding group. Hoarding and low-hoarding groups did not differ in any other EF subdomain. Hoarding symptoms in youth with OCD were not associated with deficits in EF subdomains; instead, youth who hoard exhibited higher cognitive flexibility compared to youth with low hoarding symptoms.