Autism spectrum disorder, ADHD, epilepsy, and cerebral palsy in Norwegian children.
BACKGROUND
Numerous studies have investigated the prevalence of neurologic and neurodevelopmental disorders individually, but few have examined them collectively, and there is uncertainty as to what extent they overlap.


METHODS
The study has determined the proportions of children aged 0 to 11 years with diagnoses of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), epilepsy, and cerebral palsy (CP) in Norway. The data were obtained from the Norwegian Patient Register, which is nationwide and contains diagnoses assigned by Norwegian specialist health services (hospitals and outpatient clinics). The Norwegian Patient Register started collecting individual-level data in 2008, and the follow-up period for the study is years 2008 through 2010.


RESULTS
For ASD, ADHD, and epilepsy, the proportions were highest in the oldest children. At age 11 years, the incidence was 0.7% for ASD, 2.9% for ADHD, and 0.9% for epilepsy. The cumulative incidence is likely to be higher because some cases diagnosed before 2008 were probably missed. For CP, the proportions were ~0.3% for age ≥ 5 years. There was considerable overlap between diagnoses. For all disorders, boys had a significantly increased risk. In school-age children (aged 6-11 years) the male/female ratio was 4.3 for ASD, 2.9 for ADHD, 1.2 for epilepsy, and 1.3 for CP.


CONCLUSIONS
The findings demonstrate the significant burden of disease associated with neurologic and neurodevelopmental disorders in children and that this burden is disproportionately skewed toward boys.
Centre for Paediatric Epidemiology and Biostatistics, University College London Institute of Child Health, London, United Kingdom. pal.suren@fhi.no
Pål
P
Surén
Inger Johanne
IJ
Bakken
Heidi
H
Aase
Richard
R
Chin
Nina
N
Gunnes
Kari Kveim
KK
Lie
Per
P
Magnus
Ted
T
Reichborn-Kjennerud
Synnve
S
Schjølberg
Anne-Siri
AS
Øyen
Camilla
C
Stoltenberg
D017677:Age Distribution; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology*; D002547:Cerebral Palsy / Q000453:epidemiology*; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000453:epidemiology*; D002675:Child, Preschool; D015897:Comorbidity; D004827:Epilepsy / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009664:Norway / Q000453:epidemiology; D012042:Registries; D017678:Sex Distribution