Young children with autism spectrum disorder (ASD) often have gross motor delays (GMD) that may accentuate problem daytime behavior (PDB) and health-related quality of life (QoL).
The objective of this study was to describe the degree of GMD in young children with ASD and associations of GMD with PDB and QoL. The primary hypothesis was that GMD significantly modifies the associations between internalizing or externalizing PDB and QoL.
This study used a cross-sectional, retrospective analysis.
Data from 3253 children who were 2 to 6 years old and who had ASD were obtained from the Autism Speaks Autism Treatment Network and analyzed using unadjusted and adjusted linear regression. Measures included the Vineland Adaptive Behavior Scales, 2nd edition, gross motor v-scale score (VABS-GM) (for GMD), the Child Behavior Checklist (CBCL) (for PDB), and the Pediatric Quality of Life Inventory (PedsQL) (for QoL).
The mean VABS-GM was 12.12 (SD = 2.2), representing performance at or below the 16th percentile. After adjustment for covariates, the internalizing CBCL t score decreased with increasing VABS-GM (β = -0.64 SE = 0.12). Total and subscale PedsQL scores increased with increasing VABS-GM (for total score: β = 1.79 SE = 0.17; for subscale score: β = 0.9-2.66 SE = 0.17-0.25). CBCL internalizing and externalizing t scores decreased with increasing PedsQL total score (β = -0.39 SE = 0.01; β = -0.36 SE = 0.01). The associations between CBCL internalizing or externalizing t scores and PedsQL were significantly modified by VABSGM (β = -0.026 SE = 0.005]; β = -0.019 SE = 0.007).
The study lacked ethnic and socioeconomic diversity. Measures were collected via parent report without accompanying clinical assessment.
GMD was independently associated with PDB and QoL in children with ASD. GMD modified the association between PDB and QoL. Children with ASD and co-occurring internalizing PDB had greater GMD than children without internalizing PDB; therefore, these children may be most appropriate for early physical therapist evaluation.