Publication | The social patterning of autism diagnoses reversed in California between 1992 and 2018
by Alix S. Winter, Christine Fountain, Keely Cheslack-Postava, and Peter S. Bearman
Interdisciplinary Center for Innovative Theory and Empirics, Columbia University
Department of Sociology & Anthropology. Fordham University at Lincoln Center
New York State Psychiatric Institute, Columbia University
Rates of autism diagnosis in the United States have increased dramatically over the past few decades. Historically, rates of diagnosis have been highest among more advantaged social groups – people who are White and of higher socioeconomic status (SES). Newly published research by Columbia University’s Interdisciplinary Center for Innovative Theory and Empirics’ Understanding Autism project shows that rates of autism diagnosis continued to rise through 2018. But the demographics of who was diagnosed changed during the study period.
The authors show that California’s diagnosed autism incidence rate rose from 0.49 per 1,000 3 to 6 year olds in 1998 to 3.49 per 1,000 3 to 6 year olds in 2018—a 612% increase. What was most striking, though, was that, by 2018, long established patterns of autism diagnosis by sociodemographic characteristics had reversed.
In the second half of the study period, for instance, children of Black and Asian mothers were diagnosed with autism at higher rates than children of non-Hispanic White mothers. Indeed, between 1998 and 2018, diagnosed autism incidence rates rose 633% among children of Black mothers, but only 350% among children of non-Hispanic White mothers. Additionally, among children of non-Hispanic White and Asian mothers, children of lower SES mothers were diagnosed at higher rates than children of higher SES mothers. While diagnosed autism incidence rates rose 283% among children of higher SES, non-Hispanic White mothers between 1998 and 2018, autism incidence rates rose 875% among children of lower SES, non-Hispanic White mothers over the same period.
Peter Bearman, co-Principal Investigator on the project, said, “These results suggest that, over the past decade, there has been improved access to diagnosis and services for parents and families with fewer resources.”
Christine Fountain, also co-Principal Investigator on the project, commented, “The unexpected reversal of the socioeconomic gradient for autism, even as diagnoses continued to rise, reveals how important it is to examine how race and economic status shape health and diagnostic patterns over time.”
To conduct the analysis, the authors drew on the birth records of all children born in the state of California from 1992 through 2016 and linked those with autism caseload records from January 1992 through November 2019 from California’s Department of Developmental Services.
Read more in: Winter, Alix S., Christine Fountain, Keely Cheslack-Postava, Peter S. Bearman. 2020. “The social patterning of autism diagnoses reversed in California between 1992 and 2018.” Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.2015762117.