A new study of children diagnosed with autism in the US has found that socioeconomic inequalities in who is diagnosed with autism are less marked than they used to be. As knowledge has spread about autism over the last two decades, it is increasingly likely that children from communities and families across the socioeconomic spectrum will be diagnosed with it. But researchers found that poor children from low-income neighborhoods are still being under-diagnosed.
The study examines birth and diagnostic records for all children born in California between 1992 and 2000 in conjunction with individual and community-level data such as parental wealth, parental education, and neighborhood property value. All children were followed from the time of birth until June 2006 to allow ample time for diagnosis. As the disorder became increasingly well-known, the average age of autism diagnosis fell from 5.9 among those children born in 1992 to 3.8 for those born in 2000.
“At the height of rising prevalence, which involved children born between 1992 and 1995, kids whose parents had fewer economic resources simply weren’t diagnosed as often as wealthier children— wealthier kids were 20 to 40% more likely than poorer children to be diagnosed,” said study coauthor Marissa D. King, an assistant professor of Organizational Behavior at Yale University’s School of Management “Among children born in 2000, however, parental wealth alone had no effect on the likelihood that a child would be diagnosed.”
Overall, of the 4,906,926 million children born in California between 1992 and 2000, 18,731 or .38% were diagnosed with autism. The prevalence of autism among the 1992 through 2000 California birth cohorts increased significantly, from 29 per 10,000 in 1992 to 49 per 10,000 in 2000.