FRIDAY, Dec. 18 (HealthDay News) -- Improved documentation and identification of children with Autism Spectrum Disorders (ASDs) may have contributed to a rise in prevalence from 2002 to 2006, but an increased risk of developing an ASD should not be discounted, according to a surveillance summary published Dec. 18 in the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.
Catherine Rice, Ph.D., of the CDC's National Center on Birth Defects and Developmental Disabilities in Atlanta, and colleagues assessed the prevalence of ASDs in 8-year-old children whose parents lived in 11 Autism and Developmental Disabilities Monitoring (ADDM) Network sites in the United States in 2006.
The report states that, in the ADDM sites, 0.9 percent of the nearly 308,000 8-year-olds were identified as having an ASD, with an average prevalence of nine children per 1,000. The ASD prevalence was higher in sites with access to medical and education records (10.0), as compared to sites with medical records alone (7.5). Among 10 ADDM sites involved in both 2002 and 2006 surveillance studies, nine cited an increase in ASD prevalence.
"The average prevalence of ASDs identified among children aged 8 years increased 57 percent in 10 sites from the 2002 to the 2006 ADDM surveillance year. Although improved ascertainment accounts for some of the prevalence increases documented in the ADDM sites, a true increase in the risk for children to develop ASD symptoms cannot be ruled out," the authors write.
