The Danish National Hospital Register is a valuable study base for epidemiologic research in febrile seizures

Background and ObjectivesWe examined the quality and completeness of the discharge diagnosis of febrile seizures in the Danish National Hospital Register (DNHR).MethodsWe 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.ResultsWe 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).ConclusionThe Danish National Hospital Register is a valuable tool for epidemiologic research in febrile seizures.