Expressive language sampling and outcome measures for treatment trials in fragile X and down syndromes: composite scores and psychometric properties

• Type of Material: Article
• Authors: Leonard Abbeduto, University of California Davis Health; Laura del Hoyo Soriano, University of California Davis Health; Elizabeth Berry-Kravis, Rush University Medical Center; Audra Sterling, Waisman Center; Jamie O Edgin, The University of Arizona; Nadia Abdelnur, UC Davis MIND Institute; Andrea Drayton, UC Davis MIND Institute; Anne Hoffmann, Rush University; Debra Hamilton, Emory University; Danielle J Harvey, University of California, Davis; Angela John Thurman, University of California Davis Health
• Language: English
• Date: 2023-12-01
• Publisher: Springer Nature Limited
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2023
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/s41598-023-36087-3
• Title of Journal or Parent Work: Scientific Reports
• Volume: 13
• Issue: 1
• Start Page: 9267
• End Page: 9267
• Keywords: Vocabulary; Humans; Psychometrics; Language; Reproducibility of Results; Outcome Assessment, Health Care
• Research Categories: Psychology, Behavioral; Health Sciences, Medicine and Surgery

Abstract

The lack of psychometrically sound outcome measures has been a barrier to evaluating the efficacy of treatments proposed for core symptoms of intellectual disability (ID). Research on Expressive Language Sampling (ELS) procedures suggest it is a promising approach to measuring treatment efficacy. ELS entails collecting samples of a participant’s talk in interactions with an examiner that are naturalistic but sufficiently structured to ensure consistency and limit examiner effects on the language produced. In this study, we extended previous research on ELS by analyzing an existing dataset to determine whether psychometrically adequate composite scores reflecting multiple dimensions of language can be derived from ELS procedures administered to 6- to 23-year-olds with fragile X syndrome (n = 80) or Down syndrome (n = 78). Data came from ELS conversation and narration procedures administered twice in a 4-week test–retest interval. We found that several composites emerged from variables indexing syntax, vocabulary, planning processes, speech articulation, and talkativeness, although there were some differences in the composites for the two syndromes. Evidence of strong test–retest reliability and construct validity of two of three composites were obtained for each syndrome. Situations in which the composite scores would be useful in evaluating treatment efficacy are outlined.