Socioeconomic Inequality in the Prevalence of Autism Spectrum Disorder: Evidence from a U.S. Cross-Sectional Study

Abstract

BackgroundThis study was designed to evaluate the hypothesis that the prevalence of autism spectrum disorder (ASD) among children in the United States is positively associated with socioeconomic status (SES).MethodsA cross-sectional study was implemented with data from the Autism and Developmental Disabilities Monitoring Network, a multiple source surveillance system that incorporates data from educational and health care sources to determine the number of 8-year-old children with ASD among defined populations. For the years 2002 and 2004, there were 3,680 children with ASD among a population of 557 689 8-year-old children. Area-level census SES indicators were used to compute ASD prevalence by SES tertiles of the population.ResultsPrevalence increased with increasing SES in a dose-response manner, with prevalence ratios relative to medium SES of 0.70 (95% confidence interval [CI] 0.64, 0.76) for low SES, and of 1.25 (95% CI 1.16, 1.35) for high SES, (P<0.001). Significant SES gradients were observed for children with and without a pre-existing ASD diagnosis, and in analyses stratified by gender, race/ethnicity, and surveillance data source. The SES gradient was significantly stronger in children with a pre-existing diagnosis than in those meeting criteria for ASD but with no previous record of an ASD diagnosis (p<0.001), and was not present in children with co-occurring ASD and intellectual disability.ConclusionsThe stronger SES gradient in ASD prevalence in children with versus without a pre-existing ASD diagnosis points to potential ascertainment or diagnostic bias and to the possibility of SES disparity in access to services for children with autism. Further research is needed to confirm and understand the sources of this disparity so that policy implications can be drawn. Consideration should also be given to the possibility that there may be causal mechanisms or confounding factors associated with both high SES and vulnerability to ASD.

Parental concerns, socioeconomic status, and the risk of autism spectrum conditions in a population-based study

“…Recent studies on the association between socioeconomic status and the risk of autism reported conflicted results (Durkin et al, 2010;King & Bearman, 2011;Rai et al, 2012). Inequality in access to service due to different SES status of parents is not unusual.…”

“…In twelve ADDM sites using socioeconomic status (SES), the prevalence ratio for low to medium SES was 0.7 (95%CI: 0.64, 0.76) and that for high to medium SES was 1.25 (95%CI: 1.16, 1.35), regardless of whether a child had a pre-existing ASC diagnosis or not (Durkin et al, 2010). However, in the most recent study in Sweden, children of families with low incomes and parents with manual occupations were found to have a higher risk of ASC (odds ratio=1.4, 95%CI: 1.3-1.6) (Rai et al, 2012).…”

Parental Age and Cognitive Disability among Children in the United States

“…The prevalence of developmental disabilities and intellectual disability is thus higher in low-income families, although autism may be more often diagnosed in families with more highly educated parents (Leonard et al 2011;Durkin et al 2010;King & Bearman 2011). Some conditions, such as intellectual disability and Down syndrome, are found at varying rates across racial and ethnic groups in the U.S., although the mechanisms for these patterns are unknown (Griffin, Mann & McDermott 2011;Sherman et al 2010).…”

BACB Certification Trends: State of the States (1999 to 2014)

“…Not surprisingly, states with higher populations have higher numbers of BACB certificants. After all, states with larger populations might also be expected to have greater demand for ABA service providers, considering that ASD is reported to occur in all racial, ethnic, and socioeconomic groups (Durkin et al 2010). Additionally, these states might also have a larger pool of professionals who are pursuing a career in behavior analysis.…”