title: Long-term risk of developing epilepsy after febrile seizures: a prospective cohort study.
abstract: OBJECTIVE
  We report the prospective follow-up of a cohort of people from the onset of febrile seizures for a median of 24 years to estimate the long-term risk of developing epilepsy.
  
  
  METHODS
  The National General Practice Study of Epilepsy is a large prospective community study of 1,195 people with a first suspected seizure followed from the 1980s, of whom 220 (18%) had febrile seizures. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) for subsequent epilepsy were calculated in 5-year age bands.
  
  
  RESULTS
  Follow-up information was obtained for 181 (83%) people with a mean follow-up for the whole cohort of 21.6 (SD 6.0) years. Of these, 175 (97%) were seizure-free in the preceding 5 years, whereas 171 (94%) were seizure-free and off antiepileptic drugs. Six percent developed epilepsy, but the risk of developing epilepsy in the cohort over the whole follow-up period was almost 10 times that of the general population (SIR 9.7, 95% CI 5.7-16.4). The SIR was significantly elevated in the 0- to 14-year age groups but not in the 15- to 19-year age group (SIR 4.5, 95% CI 0.6-32.1).
  
  
  CONCLUSIONS
  The risk of developing epilepsy in people who had febrile seizures seems to decrease with time. Further long-term studies are needed to confirm this.
authors.affiliation: Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Neligan
authors.forename: G S
authors.initials: GS
authors.lastname: Bell
authors.forename: C
authors.initials: C
authors.lastname: Giavasi
authors.forename: A L
authors.initials: AL
authors.lastname: Johnson
authors.forename: D M
authors.initials: DM
authors.lastname: Goodridge
authors.forename: S D
authors.initials: SD
authors.lastname: Shorvon
authors.forename: J W
authors.initials: JW
authors.lastname: Sander
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000927:Anticonvulsants / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004198:Disease Susceptibility; D004827:Epilepsy / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D005194:Family Practice / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D003294:Seizures, Febrile / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000927:Anticonvulsants