title: Comorbidity and Childhood Epilepsy: A Nationwide Registry Study.
abstract: Children with epilepsy are at increased risk of other disorders and difficulties, preceding, cooccurring with, or after the diagnosis of epilepsy. Risk estimates vary, few studies are population-based, and few provide comprehensive assessments of comorbidities. We used nationwide registry data to describe frequencies of medical, neurologic, developmental, and psychiatric conditions occurring before and after children are diagnosed with childhood epilepsy.
  
  
  
  Data were obtained from the Norwegian Patient Registry, which is an administrative database recording International Classification of Diseases, 10th Revision diagnoses from all government-funded specialist health services in Norway (outpatient consultations and hospitalizations). We included data from the years 2008 through 2013 for all children born in Norway between 1996 and 2013 (0-17 years of age at the end of follow-up). Children with epilepsy were compared with the general child population, adjusting for sex and age. We also compared children with complicated epilepsies (ie, epilepsies with additional neurologic and/or developmental disorders) to children with uncomplicated epilepsies.
  
  
  
  The study population included 1 125 161 children. There were 6635 (0.6%) children with epilepsy. Nearly 80% of children with epilepsy had ≥1 comorbid disorder. All types of disorders were more frequent in children with epilepsy, with additional medical disorders recorded in 55%, neurologic disorders in 41%, and developmental/psychiatric disorders in 43%. Children with complicated epilepsies had the highest overall levels of comorbidity, but the risk of medical and psychiatric comorbidities was also substantial among children with uncomplicated epilepsies.
  
  
  
  The overall frequency of comorbid disease is high in children with epilepsy, including children with presumably uncomplicated epilepsies.
authors.affiliation: Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway; National Center for Epilepsy, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway; kari.modalsli.aaberg@fhi.no.
authors.forename: Kari Modalsli
authors.initials: KM
authors.lastname: Aaberg
authors.affiliation: Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway;
authors.forename: Inger Johanne
authors.initials: IJ
authors.lastname: Bakken
authors.affiliation: National Center for Epilepsy, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway;
authors.forename: Morten I
authors.initials: MI
authors.lastname: Lossius
authors.affiliation: Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway;
authors.forename: Camilla
authors.initials: C
authors.lastname: Lund Søraas
authors.affiliation: Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway;
authors.forename: Siri Eldevik
authors.initials: SE
authors.lastname: Håberg
authors.affiliation: Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Global Public Health and Community Care, University of Bergen, Norway; and.
authors.forename: Camilla
authors.initials: C
authors.lastname: Stoltenberg
authors.affiliation: Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway; National Center for Epilepsy, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway;
authors.forename: Pål
authors.initials: P
authors.lastname: Surén
authors.affiliation: Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Chin
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D000013:Congenital Abnormalities / Q000453:epidemiology; D002658:Developmental Disabilities / Q000453:epidemiology; D004827:Epilepsy / Q000453:epidemiology*; D005767:Gastrointestinal Diseases / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D001523:Mental Disorders / Q000453:epidemiology; D009140:Musculoskeletal Diseases / Q000453:epidemiology; D009422:Nervous System Diseases / Q000453:epidemiology; D009664:Norway / Q000453:epidemiology; D012042:Registries