Individual disorders such as autism spectrum disorder, attention-deficit/hyperactivity disorder, epilepsy and cerebral palsy have been found to overlap in children, especially boys, according to study results.
Pål Surén, MD, MPH, of the Norwegian Institute of Public Health, and colleagues analyzed data collected on 731,318 children aged 0 to 11 years who were part of the Norwegian Patient Register, a nationwide database containing diagnoses confirmed by pediatric specialists. The researchers calculated the prevalence of diagnoses of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), epilepsy and cerebral palsy in patients treated between 2008 and 2010.
Results showed that there was a high degree of overlap between ASD and ADHD, with 17.3% of ASD cases also having diagnoses of ADHD. “Comorbid epilepsy diagnoses were found in 11.2% of the ASD cases,” the researchers wrote. “The estimated cumulative incidence of ASD was 0.7% for ages 6 to 11 years combined and 0.8% for 11-year-olds.” Comorbid diagnoses of ASD and epilepsy were also common, with 6.4% of those diagnosed ADHD having ASD diagnoses and 5.3% having epilepsy. Epilepsy diagnoses had considerable overlap with other disorders; 7.8% of registered cases of epilepsy had ADHD, 6.1% had ASD and 12.8% had cerebral palsy. Comorbid epilepsy was found in 32.5% of patients with cerebral palsy.
According to the researchers, boys were at a significantly increased risk for all disorders compared with girls. In patients aged 6 to 11 years, the male/female ratio was 4.3 for ASD (95% CI, 3.9-4.9), 2.9 for ADHD (95% CI, 2.7-3.1), 1.2 for epilepsy (95% CI, 1.1-1.3) and 1.3 for cerebral palsy (95% CI, 1.2-1.5).
“The findings demonstrate the significant burden of disease associated with such disorders in children, and they clearly show how this burden is disproportionately skewed toward boys,” the researchers wrote, adding that national registers such as the one in Norway provide excellent frameworks for surveillance and research, and make it easier to study different disorders simultaneously.
Disclosure: The researchers report no relevant financial disclosures.