Search This Blog

Saturday, March 23, 2013

The CDC Study and Prevalence

At the Bergen Record, Mary Jo Layton writes of the new CDC finding of a 1-in-50 prevalence of autism:

When New Jersey reported one of the nation’s highest rates of autism last year — doubling in six years to one in 49 children — researchers described it as “beyond an emergency.”
But a federal study released this week indicated that the high rate appears to be the norm nationally. Autism spectrum disorder now affects one in every 50 children, well above the one in 88 previously reported by the Centers for Disease Control and Prevention.
“The good news is that the increase in autism isn’t special to New Jersey,” said Walter Zahorodny, an autism researcher at the University of Medicine and Dentistry of New Jersey. “The bad news is that it’s a significant increase and it’s registering everywhere.”
“The feeling all along wasn’t that New Jersey has more cases of autism — New Jersey was just more rigorous in ascertaining the incidence,” said Dr. Joseph Holahan, medical director of the child development center at St. Joseph’s Children’s Hospital in Paterson. “It’s still one of the most common serious developmental disorders we see.”
Some experts have questioned the methodology used in the latest federal report — a national phone survey of 95,000 parents from 2011 and 2012, compared with more rigorous population-based research the CDC relied on when it estimated the 1-in-88 rate. Fewer than a quarter of the parents contacted agreed to answer questions in the general health survey, which included the questions about autism.
The survey focused on children ages 6 to 17, and the CDC attributed much of the increase to reported cases in adolescents ages 14-17. These children were more likely to have milder symptoms and therefore were not diagnosed until later, CDC experts concluded.

“This is a good study, done with a large U.S. sample, and it correctly reflects the magnitude of increase in autism spectrum disorder over the past years,” Zahorodny said.
But he urged caution. As a telephone survey, he said, “it may be biased from the perspective of who responds.”