A new analysis of data on childhood ADHD by CDC researchers finds that estimates based on parent reports of the condition do not appear to overestimate its prevalence.
Estimates of the prevalence of attention-deficit/hyperactivity disorder (ADHD) have been disputed for years, with many—including clinicians and members of the general public alike—convinced that the condition has been over-diagnosed. In particular, some critics question the practice of basing estimates of ADHD’s prevalence on reports from parents and teachers. According to a new analysis of a large children’s health study, however, ADHD reports from parents appear to be highly accurate.
published in the March 2013 issue of JAMA Pediatrics
challenged ADHD-prevalence estimates based on reports from parents and teachers. In the study, researchers analyzed data on more than 842,000 children covered by the Kaiser Permanente Southern California health plan from 2001 to 2010. They found that 4.9% of children aged 5 to 11 years met ADHD criteria, and compared it with higher previous estimates based on parent and teacher reports. Their conclusion: Parent and teacher reports have led to overinflated estimates of ADHD’s prevalence.
Researchers at the Centers for Disease Control and Prevention (CDC), who had produced these previous estimates, were concerned that the patient sample used in the Kaiser Permanente study was not comparable to the one they had used, so they revisited the issue in a research letter
published online on May 13, 2013, in JAMA Pediatrics
. The CDC researchers’ previous estimate of ADHD prevalence
, which was based on the 2007 National Children's Health Survey, led to the conclusion that parent-reported ADHD prevalence for children aged 4 to 17 had increased from 7.8% to 9.5% between 2003 and 2007.
To make for a better comparison, the CDC researchers pared down the data used in their previous study to a sample that was similar to that used in the Kaiser Permanente study: children aged 5 to 11 and living in California who had health insurance. While the CDC researchers had found that 6.2% of all Californians aged 4 to 17 had ADHD in 2007, they found that the rate among insured Californians aged 5 to 11 was 4.7%—very close to the finding in the Kaiser Permanente study. In addition, the CDC researchers’ overall estimate of an ADHD prevalence of 9.5% in 2007 among children 4 to 17 increased to 9.8% when they limited their analysis to insured children of the same age.
Based on their analysis, the CDC researchers conclude that the Kaiser Permanente actually helps to affirm the accuracy of parent reports of ADHD rather than calling it into question. "Specifically, the [California] study ... provides evidence of convergent validity that demonstrates the appropriateness of parent report for monitoring state-based and national prevalence of ADHD," the CDC researchers write.
The CDC supports the National Resource Center on ADHD
, a program of Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD
). Their websites provide links to information based on the current best medical evidence concerning ADHD. In addition, the National Resource Center call center (800-233-4050) has trained bilingual staffers available to answer questions about ADHD.
Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy and a freelance writer from Virginia.