Predictors of recurrent febrile seizures: a metaanalytic review

The 1980 National Institutes of Health Consensus Development Conference on Febrile Seizures identified five circumstances in which it might be appropriate to consider anticonvulsant prophylaxis after a first febrile seizure: (1) a focal or prolonged seizure, (2) neurologic abnormalities, (3) afebrile seizures in a first-degree relative, (4) age less than 1 year, and (5) multiple seizures occurring within 24 hours. We performed a metaanalysis of 14 published reports to evaluate the strength of association between each of these indications and recurrent febrile seizures. Young age at onset (less than or equal to 1 year) and a family history of febrile seizures (not listed in the recommendations) each distinguished between groups with approximately a 30% versus a 50% risk of recurrence. Family history of afebrile seizures was not consistently associated with an increased risk. Focal, prolonged, and multiple seizures were associated with only a small increment in risk of recurrence. The data were not adequate to assess the risk associated with neurologic abnormalities. By considering children with combinations of risk factors, some studies were able to distinguish between groups with very low and very high recurrence risks. Only age at onset was consistently predictive of having more than one recurrence. These results suggest that the great majority of children who have a febrile seizure do not need anticonvulsant treatment even if one of the factors listed in the Consensus Statement is present, and that the rationale and indications for treating febrile seizures need to be reconsidered.