1,675,643 children born in Denmark between January 1, 1977, and December 31, 2004, were identified by linking registers for civil service, health, and cause of death, and followed-up from 3 months of age until death, emigration, or August 31, 2005. Of a total of 8172 deaths, 232 occurred in 55,215 children who had a history of febrile seizures. The mortality rate ratio was 80% higher during the first year after a first febrile seizure and 90% higher during the second year after the seizure but, thereafter, was close to that seen for the general population. There were 132 deaths per 100,000 children within 2 years of a febrile seizure versus 67 deaths per 100,000 in those without a history of febrile seizure. In a nested case-control study within the cohort, information retrieved from medical records on febrile seizures and neurological abnormalities in the 8172 children who died and 40,860 individually matched control subjects revealed that children with simple (≤15 min and no recurrence within 24 h) febrile seizure had a mortality rate similar to that of the general population, whereas mortality was increased for those with complex seizures.
