The rate of attention-deficit/hyperactivity disorder diagnosis among children treated at Kaiser Permanente Southern California increased from 2001 to 2010, according to findings published today in JAMA Pediatrics.
“The findings suggest that the rate of ADHD diagnosis among children in the health plan notably has increased over time,” researchers wrote. “We observed disproportionately high ADHD diagnosis rates among white children and notable increases among black girls.”
Darios Getahun, MD, PhD, of the Kaiser Permanente Southern California (KPSC) Medical Group in Pasadena, and colleagues examined patient medical records to document trends in the diagnosis of ADHD in 842,830 children aged 5 to 11 years who received care at KPSC.
According to the researchers, rates of ADHD diagnosis were 2.5% in 2001 vs. 3.1% in 2010, a relative increase of 24%. During the same period, the rate of ADHD diagnosis increased among whites (4.7% to 5.6%; RR=1.3; 95% CI, 1.2-1.4), blacks (2.6% to 4.1%; RR=1.7; 95% CI, 1.5-1.9) and Hispanics (1.7% to 2.5%; RR=1.6; 95% CI, 1.5-1.7). Rates of diagnosis among Asian/Pacific Islander and other racial groups remained unchanged.
The rate increase among blacks was largely due to a growing number of girls with an ADHD diagnosis (RR=1.9; 95% CI, 1.5-2.3). Boys were more likely than girls to be diagnosed with ADHD, but study results indicated that the sex gap may be closing among blacks. The researchers also observed a much higher rate of ADHD diagnosis among children living in high-income ($70,000 per year or more) households (P<.001).
“Although the reasons for increasing ADHD rates are not well understood, contributing factors may include heightened ADHD awareness among parents and physicians, increased use of screening and other preventive services, and variability in surveillance methods among institutions,” the researchers wrote.
Disclosure: The researchers report no relevant financial disclosures.