CDC Releases Report on Rate of Autism in the United States

Autism is regularly classified with Asperger’s syndrome and pervasive developmental disorder not otherwise specified to make up what are known as the autism spectrum disorders, which are diagnosed by observing developmental patterns and behaviors. The Centers for Disease Control and Prevention (CDC) conducted two surveys, the National Health Interview Survey (NHIS) and the National Survey of Children’s Health (NSCH), to determine the prevalence of autism spectrum disorders. The report, “Mental Health in the United States: Parental Report of Diagnosed Autism in Children Aged 4–17 Years—United States, 2003–2004,” was published in the May 5, 2006, issue of Morbidity and Mortality Weekly Report.

The report indicated that up to six per 1,000 children had a parent-reported diagnosis of autism. Parents who reported that their child had autism noted that the child had specialized needs and social, behavioral, or emotional symptoms.

The NHIS included 18,885 children and the NSCH involved 79,590 children. The survey results suggested that the prevalence of autism was four times as high for males compared with females, and the peak prevalence was noted in children six to 11 years of age. Children of Hispanic ethnicity had lower rates of diagnosed autism, but it was not known whether differences in etiologic or cultural factors and access to services for diagnosis and treatment affected this population.

Eighty-three percent of children whose parents reported a diagnosis of autism had moderate or high levels of difficulties (e.g., conduct problems, emotional symptoms) compared with 15 percent of children who did not have autism. Only 16 percent of children without autism had peer problems compared with 82 percent of children with an autistic disorder; and 65 percent of children with autism were hyperactive compared with 12 percent of children without autism.

About 94 percent of children who had autism had special health care needs that were expected to last 12 months or longer; and 90 percent of children with autism required additional medical, educational, and mental health services, or required counseling or treatment for a behavioral, developmental, or emotional problem compared with children of the same age who did not have autism.

Tracking patterns of development and observing behavior are the only ways to diagnose and assess autism in children, which makes establishing and tracking prevalence difficult. Therefore, family physicians may find multiple methods for case ascertainment to be helpful. The report also emphasizes that physicians should not use age, race, or ethnicity to infer potential etiologic associations.