db‐Macartney 2017.

Study characteristics
Methods	Self‐controlled case series, Australia. From 2009 to 2012
Participants	Children aged 11 to 23 months. Analysis was further restricted to include only children who had: (1) 1 dose of MMR vaccine followed by 1 dose of MMRV vaccine at least 27 days later (consistent with NIP recommendations); (2) 1 dose of MMR vaccine (as some had not yet received MMRV vaccine); or (3) no MMR or MMRV vaccine (unvaccinated children, who contribute to the age‐specific relative incidence). Children who received MMRV vaccine as their first MCV were excluded because this schedule was not consistent with NIP recommendations and rarely occurred. Because age is a strong predictor of FS and is time varying, all models were adjusted for the effect of age (using 3 age groups in the base case: 11 to 14, 15 to 18, and 19 to 23 months). We removed the −1‐ to −13‐day period before vaccination from the baseline time because it may be associated with a lower FS risk (an FS occurrence may delay receipt of scheduled vaccines).
Interventions	MMRV Priorix‐Tetra
Outcomes	Febrile seizures: in all children younger than 5 years. Periodic review of all ICD10‐Australian Modification–coded R56.0 was also conducted to capture additional cases. Clinical and demographic data were collected from the medical records and caregiver interviews, and all FS diagnoses were confirmed. The study outcome was immunisation coverage of consecutive, 3‐month national cohorts of children born between 1 January 2009 and 31 December 2012, who had reached the ages of 24, 36, 48, and 72 months, respectively, for receipt of MMR, varicella, and/or MMRV vaccine by December 2015.
Funding Source	Government
Notes	Authors' conclusions: "To our knowledge, this is the first study to provide evidence of the absence of an association between use of MMRV vaccine as the second dose of MCV in toddlers and an increased risk of FSs. Incorporation of MMRV vaccine has facilitated improvements in vaccine coverage that will potentially improve disease control."
Risk of bias
Bias	Authors' judgement	Support for judgement
SCCS/PTC ‐ case selection	Low risk	Adequate ‐ independent validation
SCCS/PTC ‐ exposure	Low risk	Adequate ‐ secure record
SCCS/PTC ‐ observation and exposure risk period	Low risk	Adequate ‐ observation periods are well‐defined, exposure period appears to be well‐documented
SCCS/PTC ‐ comparability	Low risk	Adjusted by age
Summary Risk of Bias assessment	Low risk	Plausible bias is unlikely to have seriously altered the results.