WEDNESDAY, Sept. 4, 2019 (HealthDay News) -- The prevalence of autism spectrum disorder (ASD) has increased significantly during the past 10 to 20 years and will continue to increase among all race and ethnicity groups in the coming years, according to a study published online Aug. 21 in the Journal of Autism and Developmental Disorders.
Cynthia Nevison, Ph.D., from the University of Colorado in Boulder, and Walter Zahorodny, Ph.D., from Rutgers University in Newark, New Jersey, used data from the U.S. Individuals with Disabilities Education Act (IDEA) to identify race-specific time trends in ASD prevalence among children aged 3 to 5 years. Similar trends were identified among children aged 8 years old using data from the Autism and Developmental Disabilities Monitoring (ADDM) Network.
The researchers found that ASD prevalence among white children had been higher than other racial groups but plateaued in the IDEA birth cohorts between 2004 and 2007 before increasing again. In the IDEA cohort, ASD prevalence among black and Hispanic children increased continuously and caught up to whites by birth years 2008 and 2013, respectively. ASD among black children subsequently exceeded the prevalence among white children in the majority of states. In some ADDM states, there was a plateau in the prevalence of ASD among white children for birth years 2002 to 2006; however, the IDEA trends suggest prevalence will increase across all racial groups in the ADDM birth year 2008 report.
"Our data contradict the assertion that these increases are mainly due to better awareness among minority children," Zahorodny said in a statement. "If the minority rates are exceeding the white rates, that implies some difference in risk factor, either greater exposure to something in the environment or another trigger."