| Study characteristics |
| Methods |
Case‐only ecological method. Surveillance study carried out in Rio Grande do Sul (Brazil) following an immunisation campaign with MMR vaccine containing Leningrad‐Zagreb mumps strain. |
| Participants |
Children between 1 and 11 with aseptic meningitis. |
| Interventions |
Immunisation with Leningrad‐Zagreb MMR vaccine |
| Outcomes |
Risk association with aseptic meningitis |
| Funding Source |
Government |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| COEM ‐ case selection |
Low risk |
Adequate ‐ independent validation |
| COEM ‐ exposure |
Unclear risk |
Self‐reported |
| COEM ‐ time trend comparison |
Low risk |
Adequate ‐ periods are well‐defined |
| COEM ‐ comparability |
Unclear risk |
Stratified by age |
| Summary Risk of Bias assessment |
Unclear risk |
We had concerns regarding at least 1 domain such that some doubt is raised about the results. |
