Objectives: This study describes the methodology of a large national survey that aims to characterize sensory features in children with ASD using the SEQ, and presents results from a confirmatory factor analysis used to test a conceptual model of sensory features in ASD.
Methods: Data were collected as part of a national online survey from 1308 participants with an ASD diagnosis, ages 2-12 years. The SEQ was converted to an electronic format in Qualtrics and distributed through an online national research registry and multiple autism organizations. Sample consisted of 1069 boys (CA 93 (34) mos.) and 239 girls (CA 96 (35) mos.). ASD symptom severity was assessed using the Social Responsiveness Scale (SRS/SRS-P). A factor analytic model with six substantive factors of hypothesized sensory response patterns (i.e., hyporesponsiveness, hyperresponsiveness, seeking, enhanced perception, social context, non-social context) and six method factors of sensory modalities (i.e., auditory, visual, tactile, gustatory, vestibular, multi-sensory) were tested. Method factors provide a parsimonious technique for modeling shared error variance. Model was fit as a confirmatory factor analysis. Correlations between the substantive factors were freed, but fixed to zero between the method factors, as well as between the method factors and the substantive factors.
Results: The above structure was tested as a confirmatory factor analysis. Model fit was assessed using standard fit measures: chi-square (3889) = 14,458.12, RMSEA =.04 and SRMR =.06. The latter two measures indicate strong model fit. Factor loadings for the items on the latent variables were generally strong and provided excellent support for each of the hypothesized factors. Between-factor correlations were high, ranging from .29 to .71, which implies that while these factors are distinct, they covary significantly.
Conclusions: The survey was a feasible method of obtaining a large national, geographically distributed sample. The large sample allowed a complex hypothesized model to be confirmed for a specified factor structure, including sensory response patterns in ASD across both social and non-social contexts. Further analyses will determine the extent to which there are significant associations between the substantive factors and various demographic variables (i.e. autism severity, IQ, gender, age).
See more of: Clinical Phenotype
See more of: Symptoms, Diagnosis & Phenotype