The most comprehensive study of autism to date shows that in Maryland and 13 other states the disorder is common and often diagnosed too late for effective therapies, according to the federal Centers for Disease Control and Prevention.
By analyzing youngsters' school and health records, the CDC found that one out of every 150 8-year-olds demonstrated symptoms of autism, a slightly higher rate than previous studies.
The overall figure held as well for Maryland, where the incidence rate of so-called autism spectrum disorders was in the middle of the 14 states surveyed.
"Our estimates are becoming better and more consistent, though we can't yet tell if there is a true increase in ASDs or if the changes are the result of our better studies," said the CDC's director, Dr. Julie L. Gerberding.
"We do know, however, that these disorders are affecting too many children."
Doctors and parents of autistic children seized on the figures as confirmation that autism is a serious national problem.
"It's enormous. This suggests everyone is going to know someone who has a kid with autism," said Dr. Gary Goldstein, a pediatric neurologist and president and chief executive of the Kennedy Krieger Institute in Baltimore, which specializes in children's developmental disabilities.
CDC researcher Catherine Rice cautioned against drawing national conclusions from the data because the states and subdivisions surveyed were not demographically representative of the entire country. But she said the consistency of the results from state to state was impressive.
The study, which looked at autism rates in 2000 and 2002, also found Maryland children in the middle when it came to the age of diagnosis. The most recent survey, in 2002, looked at 407,578 8-year-olds in the 14 studied areas. On average, Maryland children were diagnosed with autism at 5 years of age - two years after parents typically begin to notice tell-tale symptoms of the disorder.
Goldstein said he is concerned by delayed diagnosis because children often benefit most from therapies when they are 2 and 3 years old.
"There was a three-year lag between parents coming in and saying there is a problem and the children actually being diagnosed" he said. "They missed an important window of opportunity."
The researchers also looked at services available to autistic children in public schools. "People have historically criticized the availability of special education," Goldstein said. "But in kids with autism, if it's done right, it really helps."
