Age of Earliest Evaluation Among Linguistically Diverse 8-Year-Old Children with Autism Spectrum Disorder, Denver Metropolitan Area, 2010 - 2012

Background:  The prevalence of autism spectrum disorder (ASD) among surveillance sites in the United States is 14.6 per 1,000 8-year-old children. This prevalence varies significantly by race and ethnicity with more white, non-Hispanic children identified with ASD compared with black or Hispanic children. Compounding the understanding of prevalence among different racial and ethnic groups is the role of culture and linguistic diversity (CLD) on healthcare seeking behavior of families of persons with ASD. Children from CLD backgrounds within the US are more likely to be misdiagnosed and often diagnosed later than children who are white.

Objectives:  The purpose of this analysis is to understand linguistic diversity among children with ASD in the Denver metropolitan area and understand its role on the age children are evaluated for developmental concerns.

Methods:  Data were collected by the Colorado Autism and Developmental Disabilities Monitoring (ADDM) Project as part of the Centers for Disease Control and Prevention’s ADDM Network – a population-based surveillance system of ASD among 8-year-old children. Participants are children born in 2002 and 2004 who met the ADDM Network case definition for ASD in the 2010 and 2012 surveillance years, respectively, and resided in Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, or Jefferson counties. A child is linguistically diverse if a qualified examiner in a developmental evaluation describes the child as speaking a language other than English, lives in a household where a language other than English is spoken, or was internationally adopted at greater than 12 months of age. A child was determined to be English-speaking only when the qualified examiner did not mention another language other than English in a comprehensive evaluation.

Results:  The CO ADDM Project identified 820 children who met the ASD case definition during the 2010 and 2012 surveillance years. Among these children 85.6% were English-speaking only and 14.2% were considered linguistically diverse. Two children had an unknown language status. Compared with children who spoke English only, children who were linguistically diverse were first evaluated for developmental concerns at a younger median age (41.5 months compared with 46 months, respectively) and were more likely to have intellectual disability (IQ ≤ 70) (25.9% compared with 17.0%, respectively). When controlling for race, cognitive ability, and maternal education, linguistic diversity does not appear to effect the age at which a child is first evaluated. Rather, having intellectual disability significantly contributes to a child being seen for a developmental evaluation at earlier ages.

Conclusions:  This analysis presents a deeper understanding of linguistic diversity’s role in public health outcomes. Although linguistically diverse children are seen for a developmental evaluation at younger ages compared with English-only speaking children, this difference can be explained by the greater proportion of intellectual disability among linguistically diverse children with ASD in this surveillance dataset. Our findings suggest that linguistically diverse families may be less likely to seek an evaluation for children unless they have cognitive impairment. Further research is needed to better understand healthcare seeking behaviors of diverse families of children with ASD – with and without intellectual disability.