An earlier post mentioned the CDC finding that about 1 in 88 children has been identified with ASD.. CDC has now put the materials online. The scientific report is here. The community report is here. Here are key findss from the latter's executive summary (emphasis added):
Here are the key findings from this report:
• More children were diagnosed at earlier ages—a growing number of them by 3 years of age. Still, most children were not diagnosed until after they were 4 years of age. On average, diagnosis was a bit earlier for children with autistic disorder (4 years) than for children with the more broadly defined autism spectrum diagnoses or pervasive developmental disordernot otherwise specified (4 years, 5 months), and diagnosis was much later for children with Asperger disorder (6 years, 3 months).
• As has been detailed in previous reports, we also found that almost five times as many boys were being identified with ASDs as girls (1 in 54 compared to 1 in 252). Research exploring why there are differences in the identified prevalence among males and females is ongoing and knowing that the conditions are more common among boys can help direct our search for causes.
• The largest increases over time were among Hispanic and Black children. We suspect that some of this was due to better screening and diagnosis. However, this finding explains only part of the increase over time, as more children were identified in all racial and ethnic groups.
• The majority (62%) of children the ADDM Network identified as having ASDs did not have intellectual disability. The largest increases during 2002 to 2008 were among children without intellectual disability (those having IQ scores higher than 70), although there were increases in the identified prevalence of ASDs at all levels of intellectual ability.The New York Times reports:
C.D.C. researchers did not meet any of the children they judged to have an autism spectrum disorder. The team made the decisions based on evaluations of the children, drawn from 14 states. The estimated rates in those states varied widely, from one in 210 children in Alabama to one in 47 in Utah.
“This is a fourfold difference,” Dr. Éric Fombonne, a psychiatrist at McGill University and Montreal Children’s Hospital, said in an e-mail. “It means that ascertainment is unequal across states. Thus, in the next surveys, as ascertainment will most likely improve where it is currently low, average rates are bound to increase. Is there, in addition to this, a real increase in incidence? It’s possible, but cannot be determined from the study design.”