HealthDay News — Rates of attention-deficit/hyperactivity disorder (ADHD) diagnoses increased 25% in the last decade, study findings show.
From 2001 to 2010, ADHD diagnoses rates increased from 2.5% to 3.1%, Darios Getahun, MD, PhD, of Kaiser Permanente Southern California Medical Group in Pasadena, and colleagues reported in JAMA Pediatrics.
Rates increased among whites (relative risk =1.3; 95% CI:1.2-1.4), blacks (RR=1.7; 95% CI: 1.5-1.9) and Hispanics (RR=1.6; 95% CI: 1.5-1.7), but remained unchanged for other racial groups.
“[ADHD] is one of the most common chronic childhood psychiatric disorders, affecting 4% to 12% of all school-age children and persisting into adolescence and adulthood in approximately 66% to 85% of children,” the researchers wrote.
In order to better understand trends in ADHD diagnosis, Getahun and colleagues examined the medical records of 842,830 children aged 5 to 11 years, who received care with Kaiser Permanente Southern California between 2001 and 2010.
ADHD diagnosis was based on International Classification of Diseases, Ninth Revision, coding on child hospitalization, outpatient office visits and emergency department visits across all Kaiser facilities. Prevalence was assessed at two-year intervals and outcomes were stratified by age, race, sex and household income.
Overall ADHD prevalence was 4.9% during the 10-year study period, affecting 39,200 of 842,830 study participants, with mean patient age between 8.4 to 9.5 years at diagnosis.
Patients diagnosed with ADHD were more likely to be male than female, of white or black race/ethnicity and come from families earning more than $70,000 annually, the researchers found.
Overall, blacks had the highest relative increase in ADHD diagnosis rates (69.6%, P<0.001), largely due to an increase in ADHD prevalence among girls (RR=1.9; 95% CI:1.5-2.3). The sex gap in ADHD prevalence remained stable among other races.
“The findings suggest that the rate of ADHD diagnosis among children in the health plan notably has increased over time,” the researchers concluded. “We observed disproportionately high ADHD diagnosis rates among white children and notable increases among black girls.”
Study findings were limited by missing race data for some participants, the researchers acknowledged.