RESUMEN
LAY ABSTRACT: The increase in the prevalence of autism spectrum disorder has placed greater demands on the health care system. Children and adolescents with autism spectrum disorder often experience challenges accessing high-quality physical and mental health care due to characteristic social-communication deficits and behavioral difficulties, as well as high rates of complex medical and psychiatric comorbidities. Intellectual disability commonly co-occurs with autism spectrum disorder and individuals affected by this co-occurrence may have additional impairments that compound challenges accessing health care. This study investigated the relations among co-occurring intellectual disability, unmet physical and mental health care needs, and health care quality in a large, nationally distributed sample of youth with autism spectrum disorder using structural equation modeling techniques. Co-occurring intellectual disability was significantly associated with unmet mental health care needs in children with autism. In addition, unmet mental health care needs mediated the relationship between co-occurring intellectual disability and health care quality; youth with autism spectrum disorder and co-occurring intellectual disability who had a past-year unmet mental health need had significantly poorer caregiver-reported health care quality. These findings suggest that youth with autism spectrum disorder and co-occurring intellectual disability may be more likely to experience unmet mental health care needs and receive poorer quality of care than the broader autism spectrum disorder population.