title: The Danish National Hospital Register is a valuable study base for epidemiologic research in febrile seizures.
abstract: OBJECTIVE
  We examined the quality and completeness of the discharge diagnosis of febrile seizures in the Danish National Hospital Register (DNHR).
  
  
  METHODS
  We invited all children born at the Department of Obstetrics, Aarhus University Hospital, Denmark, between January 1990 and April 1992, to participate in the study. We collected information on febrile seizures in March 2001 by mailing a questionnaire to the mothers. Reported febrile seizures were verified by telephone interviews or review of medical records. We linked the cohort to the DNHR by means of a unique civil registry number assigned to all Danish citizens at birth. Overall, 6,624 (73%) children participated in the study.
  
  
  RESULTS
  We found that 323 (4.9%) children in the cohort had had febrile seizures, and 231 of those were registered in the DNHR (completeness: 71.5%, 95% CI: 66.3-76.4). Furthermore, we confirmed the diagnosis in 231 of 249 children registered with febrile seizures in the DNHR (predictive value of a positive registration: 92.8%, 95% CI: 88.8-95.7).
  
  
  CONCLUSIONS
  The Danish National Hospital Register is a valuable tool for epidemiologic research in febrile seizures.
authors.affiliation: The Danish Epidemiology Science Center at the Department of Epidemiology and Social Medicine, University of Aarhus, Vennelyst Boulevard 6, DK-8000 Aarhus C, Denmark. mv@soci.au.dk
authors.forename: Mogens
authors.initials: M
authors.lastname: Vestergaard
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
authors.forename: Tine Brink
authors.initials: TB
authors.lastname: Henriksen
authors.forename: Jakob
authors.initials: J
authors.lastname: Christensen
authors.forename: Kreesten Meldgaard
authors.initials: KM
authors.lastname: Madsen
authors.forename: John R
authors.initials: JR
authors.lastname: Ostergaard
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
mesh_terms: D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003718:Denmark; D006760:Hospitalization; D006761:Hospitals; D006801:Humans; D010342:Patient Acceptance of Health Care; D011237:Predictive Value of Tests; D012008:Recurrence; D012015:Reference Standards; D012042:Registries; D003294:Seizures, Febrile / Q000175:diagnosis / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D013997:Time Factors