Developing and Piloting a New Parent-Report Measure of Executive Function for Use with Children with ASD

Background:

Although executive function difficulties are well documented amongst individuals with autism spectrum disorder (ASD), there is no consensus on how best to assess these in clinical practice and research. Studies using performance-based measures (i.e., cognitive tests) often demonstrate relatively modest effect sizes and inconsistencies between studies are apparent. These findings lack ecological validity, as they do not reflect the fact that severe difficulties with planning and organisation are commonplace in the day-to-day lives of children with ASD. A widely used parent-report questionnaire measure, the Behaviour Rating Inventory of Executive Function (BRIEF), was designed to have greater ecological validity than traditional performance-based measures. A review of the literature reveals that the average score on the BRIEF for children with ASD is close to the maximum score on the BRIEF, indicating the presence of a ceiling effect.

Objectives:

The aim of this study was to develop and pilot a new parent-report measure of executive function, specifically for use with children with ASD. This measure was intended to have good ecological validity and be sensitive to variability across the full range of day-to-day executive function difficulties experienced by children with ASD.

Methods:

This research was completed in two parts. Study 1 focused on the development of the measure and Study 2 focused on its initial validation. In Study 1, parents and professionals underwent in-depth interviews about the nature of executive function difficulties in children with ASD. These interviews were analysed using qualitative methods and this directly informed the development of the new measure, thereby maximising its ecological validity. The measure was then piloted online with parents of children with ASD (N = 44) and parents of TD children (N = 55), enabling preliminary examination of its psychometric properties.

Results:

A thematic analysis of the nature of executive function difficulties in children with ASD revealed widespread executive function difficulties across multiple domains. The new measure was named the A-POD (Autism Planning and Organisation Difficulties) and initially contained 48 items. Piloting of the A-POD online revealed a large difference between the ASD and TD groups (r = .79), indicating that children with ASD were reported to have substantially greater levels of executive dysfunction. The A-POD demonstrated good test-retest reliability (r=.82) and internal consistency (α=.98). The items with the weakest reliability were removed and the final version of the A-POD contained 38 items. Preliminary positive evidence of its criterion and construct validity was found.

Conclusions:

Day-to-day executive function difficulties are substantial and widespread amongst children with ASD. The A-POD is a promising measure of these difficulties, demonstrating encouraging psychometric properties. Both parent-report and performance-based methods of assessment should be used to gain a comprehensive picture of a child’s executive function ability.