Classifying Patterns of Preschool Aged Children with Autism

Background:  Research suggests that sensory processing differences can help identify clinically meaningful subtypes, or distinct profiles, of children with ASD.  Although previous studies have used the Short Sensory Profile to determine subtypes in ASD, a recent study found that the factor structure of the Short Sensory Profile in children with ASD is characterized by patterns of sensitivity, seeking or hyporesponsiveness (Tomchek et al., 2014). Moreover, previous studies have used a wide range of ages to determine subtypes of children with ASD (Ausderau et al., 2014; Lane et al., 2014). Identifying subtypes in a sample of very young children with ASD, as well as considering the roles of sensitivity and hyporesponsiveness, may inform our understanding of sensory features for diagnostic and intervention efforts.

Objectives:  We addressed the following research questions: 1) What are the sensory subtypes, as measured by a revised factor structure of the SSP, in a sample of young children with ASD aged 3-6 years?  2) To what extent do unique subtypes differ with regard to child characteristics (i.e., sensory processing, adaptive behavior, communication)?  

Methods:  Participants included 400 children 3- 6 yrs (mean=49.57 mos.; SD=10.5 mos.).  Data was collected from children referred for evaluation received comprehensive interdisciplinary evaluations at a university affiliated tertiary diagnostic center. A Latent Profile Analysis was run to develop a model of groups of subjects who clustered on these variables. The Short Sensory Profile (SSP; McIntosh, et al., 1999) was used as the measure of sensory processing. Additional domain specific developmental measures were used to assess performance in adaptive, social, communication and motor areas.

Results:  The four profile solution was supported (BIC=5672.7; Entropy=.78), with age, adaptive functioning and sensory symptom severity defining the profiles. Age and sensory symptom severity classified children with Profiles 1 (n=63; older with generalize sensory differences) and 4 (n=94; younger with better coping and fewer sensory differences). Age, developmental functioning, and differing sensory scores allowed for interpretation of children in profiles 2 (n=42; older with higher developmental performance) and 3 (n=200; younger with lower developmental functioning).  Sensory patterns related to low energy/weak, taste/smell sensitivity, seeking, and hyporesponsivity showed variability in these subtypes and were related to child characteristics.

Conclusions:  Distinct subtypes in the current study were defined by sensory processing, age, developmental performance. These findings have relevance to the variable presentation of individuals with an ASD and allow for interpretation of phenotypes that include sensory patterns as well as child characteristics. These phenotypes likely have implications for assessment and intervention aimed at increasing children’s active engagement required for participation.  Additionally, findings may have implications for research studies investigating the etiology of ASDs and the variable responding of individuals to intervention programs.  By understanding sensory classifications we create opportunities for tailored treatment approaches that allow intervention to support individualized sensory patterns within participation.