Febrile Seizure Risk and Vaccination

Investigators from multiple institutions conducted a retrospective cohort study to estimate the risk of febrile seizures in the day following vaccination. The study population included all children aged 1–5 months who belonged to a Vaccine Safety Datalink health care organization. Data of all vaccines received by the study population from 2006–2011 were abstracted from the medical record.

Cases of febrile seizures were ascertained by identifying children over the study period who had an ED visit or inpatient admission that was associated with an ICD-9 code for convulsion. Identified children were excluded if their visit or admission occurred at a time other than on the day of or day after the administration of one or more vaccinations. Medical charts of all identified children were reviewed …