Evaluating the appropriateness of a new computer-administered measure of adaptive function for children and youth with autism spectrum disorders

Abstract

The Pediatric Evaluation of Disability Inventory-Computer Adaptive Test is an alternative method for describing the adaptive function of children and youth with disabilities using a computer-administered assessment. This study evaluated the performance of the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test with a national sample of children and youth with autism spectrum disorders aged 3–21 years. Parents (n = 365) completed an online survey that included demographics, the Social Communication Questionnaire, and the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test Social/Cognitive, Daily Activities, and Responsibility domains. Item response theory analysis confirmed items in each domain fit a unidimensional model and few items misfit. A large number of items in the Social/Cognitive domain showed differential item functioning, indicating a unique order of item difficulty in this population in this domain. Differences in item difficulty estimates were addressed through a parameter linking (equating) process. Simulations supported the accuracy and precision of the Computer Adaptive Test. Results suggest that the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test, as modified for autism spectrum disorder, is an efficient and sound assessment for this population.

Examining differential responses of youth with and without autism on a measure of everyday activity performance

“…Recent psychometric testing [7] of the PEDI-CAT (ASD), a slightly modified version of the original PEDI-CAT, with youth with autism showed acceptable values from CFA, which confirmed the validity of the three-domain structure for this group. Further, almost all items on the PEDI-CAT (ASD) had acceptable fit, indicating that items continue to fit along a unidimensional continuum for this population.…”

“…Our previous analysis indicated that the PEDI-CAT domains maintain strong psychometric properties when used with children and youth with autism [7]. However, as noted earlier, about half the items in the Social/Cognitive domain were found to have significant DIF using a logistic regression approach [7].…”

“…A key assumption underlying this universal approach is that the measurement construct will remain invariant across different populations, thus allowing comparison of the needs and outcomes of diverse groups using the same instrument [4–6]. However, some recent studies have reported that such measures may perform differently when used with specific clinical populations, particularly when the content of a scale is closely related to a primary area of impairment or functional limitation in the clinical group [7–9]. Methods derived from item response theory (IRT) have been used to investigate differences in measurement performance in clinical groups, to explore potential reasons for those differences, and identify implications for measurement development and assessment validity [10, 11].…”

“…Further, almost all items on the PEDI-CAT (ASD) had acceptable fit, indicating that items continue to fit along a unidimensional continuum for this population. However, analyses also identified significant DIF in about half of the Social/Cognitive items between youth with autism and youth without disabilities [7]. A specific pattern of social and cognitive impairments is diagnostic of autism; thus, it is not completely unexpected that differences were found in this domain.…”

Differential item functioning in the Patient Reported Outcomes Measurement Information System Pediatric Short Forms in a sample of children and adolescents with cerebral palsy

“…This approach has been applied successfully elsewhere. 17 However, if the cognitive interviews suggest that some other factor – such as lack of understanding or a different interpretation of meaning, difficulty in making the comparison implied in the item, or impact of other clinical factors such as vision or upper extremity limitations – is influencing responses, this would indicate that the responses of children and adolescents with CP are not reflecting the same construct, which is a validity issue.…”