Study suggests increased diagnosis rate of attention deficit hyperactivity disorder at health plan

A study of medical records at the Kaiser Permanente Southern California health plan suggests the rate of attention deficit hyperactivity disorder (ADHD) diagnosis increased from 2001 to 2010, according to a report published Online First by JAMA Pediatrics.

ADHD is one of the most common chronic childhood psychiatric disorders, affecting 4 percent to 12 percent of all school-aged children and persisting into adolescence and adulthood in about 66 percent to 85 percent of affected children. The origin of ADHD is not fully understood, but some emerging evidence suggests that both genetic and environmental factors play important roles, the authors write in the study background.

Darios Getahun, M.D., Ph.D., of the Kaiser Permanente Southern California Medical Group, Pasadena, Calif., and colleagues used patient medical records to examine trends in the diagnosis of ADHD in all children who received care at Kaiser Permanente Southern California (KPSC) from January 2001 through December 2010. Of the 842,830 children cared for during that time, 39,200 (4.9 percent) had a diagnosis of ADHD.

"The findings suggest that the rate of ADHD diagnosis among children in the health plan notably has increased over time. We observed disproportionately high ADHD diagnosis rates among white children and notable increases among black girls," according to the study.

The rates of ADHD diagnosis were 2.5 percent in 2001 and 3.1 percent in 2010, a relative increase of 24 percent. From 2001 to 2010, the rate increased among whites (4.7 percent to 5.6 percent); blacks (2.6 percent to 4.1 percent); and Hispanics (1.7 percent to 2.5 percent). Rates for Asian/Pacific Islanders remained unchanged over time, according to study results.

Boys also were more likely to be diagnosed with ADHD than girls, but the study results suggest that the sex gap for black children may be closing over time. Children who live in high-income households ($70,000 or more) also were at an increased risk of diagnosis, according to the results.