| Study characteristics |
| Methods |
Retrospective and prospective cohort, Denmark |
| Participants |
537,171 Danish children |
| Interventions |
Exposure to MMR vaccine (containing measles strain Moraten, mumps Jeryl Lynn, and rubella Wistar) |
| Outcomes |
Febrile seizure (ICD definition) in children aged 3 months to 5 years: cases occurred within 2 weeks after vaccination and cases occurred after this time |
| Funding Source |
Government |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| PCS/RCS ‐ exposed cohort selection |
Low risk |
Adequate ‐ representative of exposed ‐ Danish civil registration system ‐ National Board of Health |
| PCS/RCS ‐ non‐exposed cohort selection |
Low risk |
Adequate ‐ drawn from the same community ‐ Danish civil registration system |
| PCS/RCS ‐ comparability |
Low risk |
Adjusted for age, calendar period, sex, number of siblings with febrile seizures, number of siblings with epilepsy |
| PCS/RCS ‐ assessment of outcome |
Low risk |
Adequate ‐ national hospital registry |
| Summary Risk of Bias assessment |
Low risk |
Plausible bias is unlikely to have seriously altered the results. |
