Evaluating working memory outcome measures for children with Down syndrome

Abstract

Background There is a critical need for the psychometric evaluation of outcome measures to be used in clinical trials targeting cognition in Down syndrome (DS). This study examines a specific cognitive skill that is of particular importance in DS, working memory, and the psychometric properties of a set of standardised measurements to assess working memory in individuals with DS. Methods Ninety children and adolescents ages 6 to 18 years old with DS were assessed on a selection of verbal and visuospatial working memory subtests of standardised clinical assessments at two time points to examine feasibility, distributional qualities, test–retest reliability and convergent validity against a priori criteria. Caregivers also completed an adaptive behaviour questionnaire to address working memory subtests' associations with broader developmental functioning. Results The Stanford Binet‐5 Verbal Working Memory, Differential Ability Scales‐2 Recognition of Pictures, Stanford Binet‐5 Nonverbal Working Memory and Wechsler Intelligence Scale for Children‐5 Picture Span measures met the most psychometric criteria overall across the full age and IQ range of the study. Although Differential Ability Scales‐2 Recall of Sequential Order and Differential Ability Scales‐2 Recall of Digits Backward met the fewest a priori criteria, follow‐up analyses suggested greater feasibility in specific age and IQ ranges. Conclusions Several working memory measures appear to be psychometrically sound and appropriate for use in clinical trials for children with DS, especially when focusing on raw scores. However, floor effects on standard scores and feasibility of some measures were problematic. Guidelines for use of the working memory subtests with this population are provided.

Executive function and intellectual disability: innovations, methods and treatment

“…In this special issue, Schworer et al . (2022) present a comprehensive account of the psychometric properties of some of the most commonly‐used measures to assess working memory in people with Down syndrome. They found that several of these measures met their a priori criteria for reliability, validity and feasibility for their entire sample of children and adolescents with Down syndrome.…”

Psychometric Evaluation of Social Cognition and Behavior Measures in Children and Adolescents with Down Syndrome

“…Two parents reported that their child had ASD. Data from the participants in this study have been used in other manuscripts focused on the assessment of working memory outcome measures [33] and the association between executive function and adaptive skills [34].…”

“…Feasibility criteria were set a priori and ≥80% was the selected parameter for acceptable feasibility for use of these measures in DS research. This selection was informed by previous work on the psychometrics of cognitive measurements in intellectual disability and DS [33,39]. Examiners recorded reasons for noncompletion, which consisted of not understanding the task, behavioral noncompliance, and verbal refusal.…”

“…Test-retest reliability was assessed using intraclass correlation coefficients (ICC). Descriptive categories for ICCs are poor (<0.50), moderate (0.50−0.74), good (0.75−0.90), or excellent (>0.90) [33,40], and a priori good or excellent classifications were deemed suitable. Paired samples t-tests were used to assess practice effects.…”

“…Specificity probabilities estimate the likelihood that a participant not included in the specified characteristics will be unable to complete the measure. These analyses were completed for any measure that did not meet study feasibility criteria, and suggestions for age and cognitive ability of participants for future administration were established (as per [33]). Benchmarks for sensitivity and specificity probabilities were selected based on age (8 and 10 years) and cognitive ability (ABIQ deviation scores ≥20, ≥30, ≥40, and ≥50).…”