title: Socioeconomic status is a risk factor for epilepsy in Icelandic adults but not in children.
abstract: OBJECTIVE
  Two earlier population-based studies provide conflicting information on the association between low socioeconomic status (SES) and risk for epilepsy. Seizure etiologies (e.g., head injury, stroke) associated with low SES were not addressed in prior analyses. We assess the relation between SES indices and incident epilepsy separately for children and adults and in subgroups defined by seizure etiology.
  
  
  METHODS
  In this population-based case-control study, a surveillance system identified incident unprovoked seizure or first diagnosis of epilepsy throughout Iceland (n = 418). Controls were selected from the population registry as the next two same-sex births alive, residing in Iceland at the time of the index seizure, and without a history of unprovoked seizure on the date of the case's incident seizure (n = 835). The odds ratio measured the association between SES and epilepsy.
  
  
  RESULTS
  An association was found between epilepsy and SES among adults, but not among children. Among adults, low education was associated with an increased risk for epilepsy [odds ratio (OR), 2.29; 95% confidence interval (CI), 1.21-4.34), and home ownership was protective (OR, 0.63; 95% CI, 0.43-0.92). When analyses were repeated by seizure etiology, this association remained only in the group with epilepsy of unknown cause, even after adjusting for alcohol consumption.
  
  
  CONCLUSIONS
  Low SES, indexed by low education or lack of home ownership, is a risk factor for epilepsy in adults, but not in children, suggesting a cumulative effect of SES on risk for epilepsy. This association is not explained by established risk factors for epilepsy (e.g., head injury, stroke). We find no evidence of a downward social drift among cases whose parents had epilepsy.
authors.affiliation: GH Sergievsky Center, Columbia Presbyterian Medical Center, New York, New York, USA. dch5@columbia.edu
authors.forename: Dale C
authors.initials: DC
authors.lastname: Hesdorffer
authors.forename: Hong
authors.initials: H
authors.lastname: Tian
authors.forename: Kishlay
authors.initials: K
authors.lastname: Anand
authors.forename: W Allen
authors.initials: WA
authors.lastname: Hauser
authors.forename: Petur
authors.initials: P
authors.lastname: Ludvigsson
authors.forename: Elias
authors.initials: E
authors.lastname: Olafsson
authors.forename: Olafur
authors.initials: O
authors.lastname: Kjartansson
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004522:Educational Status; D004827:Epilepsy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011203:Poverty / Q000706:statistics & numerical data; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D012923:Social Class