Table 3

Presentations of febrile convulsions in children aged 6 months to 4 years to nine Perth hospital emergency departments in the 49-day period following commencement of the trivalent inactivated influenza vaccination program, 2008–2010*

YearNumber of febrile convulsion presentations within the investigation periodOR of temporally related§ febrile convulsionsp Value for difference
TotalNot temporally related§ to TIVTemporally related§ to TIVUnknown
20096865030 (0–19)0.34
2010996038144 (6–894)<0.001
  • * Unadjusted estimates of number of TIV doses given were 26 037 in 2008, 11 909 in 2009 (both derived from program data) and 11 243 in 2010 (derived from vaccine provider survey).

  • ICD-10 code R56.0 ‘febrile convulsion’. No febrile convulsions were recorded for children who had received monovalent H1N1 pandemic influenza vaccine.

  • The 49-day period allows for febrile convulsion to develop 72 h after vaccination up to day 46.

  • § A temporal relationship is defined as febrile convulsion occurring within 72 h of receiving TIV.

  • ‘Unknown’ if either not listed on the Australian Childhood Immunisation Register or uncontactable by telephone after four attempts, and immunisation provider not known. ‘Unknowns’ were excluded from statistical analysis.

  • TIV, trivalent inactivated influenza vaccine.