Rate of US Autism 1 in 70 Boys

Rate of U.S. Autism 1 in 70 Boys

December 18, 2009. The U.S. Centers for Disease Control and Prevention (CDC) released their national autism prevalence report today, confirming that the prevalence of autism spectrum disorders in the United States was 1 percent of the population, or one in 110 of children 8 years of age in 2006.

The long-awaited report was conducted by the CDC’s Autism and Developmental Disabilities Monitoring Network in 11 sites in 2006 and tracks prevalence in children 8 years of age. The Autism and Developmental Disabilities Monitoring (ADDM) Network is a group of programs funded by CDC to determine the number of people with autism spectrum disorders (ASDs) in the United States. The ADDM sites all collect data using the same surveillance methods, which are modeled after CDC’s Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP).

The study suggests that while better diagnosis accounts for some of the prevalence, a true increase cannot be ruled out.

Increases in prevalence among minority population were significant, with a 91 percent increase in Hispanic children (with 144 percent increase in Arizona contributing to this) and 41 percent in black non-Hispanic. There was a 55 percent increase in White non-Hispanic.

Prevalence in boys was found to be 4.5 times higher than girls. The report states one in 70 boys and one in 315 girls have autism.

This study gathered data on prevalence and cognitive impairment, showing a 90 percent increase in children with borderline intellectual functioning and a 72 percent increase among children with average to above average intelligence.

Overall prevalence was lower among the sites with access to health evaluations alone, so sites that did not include educational evaluations likely underestimated ASD prevalence for that site. The lack of educational data would have impacted the cognitive functioning analysis as well.

The ADDM study does not cover adult prevalence or those children who receive diagnoses later than 8, which can be common in the Asperger’s community, where the average age of diagnosis is 11 years old.

The ADDM report, which was conducted in the states of Alabama, Arizona, Colorado, Florida, Georgia, Maryland, Missouri, North Carolina, Pennsylvania, South Carolina and Wisconsin, is consistent with the Department of Health and Human Services National Survey of Children’s Health, published last October.