| Methods |
Retrospective cohort study assessing the effect of pandemic H1N1 immunisation during pregnancy on neonatal outcomes |
| Participants |
Eligible pregnant women were identified by means of electronic medical records from Kaiser Permanente (KP) managed care organisation sites in Georgia and mid‐Atlantic states. A total of 3327 third‐trimester live births to 3236 mothers between 25 May 2009 and 17 April 2010 were included. |
| Interventions |
Immunisation with H1N1 pandemic vaccine |
| Outcomes |
Preterm birth (27 to 36 weeks), low birth weight |
| Notes |
Government funded |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| PCS/RCS ‐ selection exposed cohort
All outcomes |
Unclear risk |
KP registry |
| PCS/RCS ‐ selection non‐exposed cohort
All outcomes |
Unclear risk |
KP registry |
| PCS/RCS ‐ comparability
All outcomes |
High risk |
Possible residual confounding |
| PCS/RCS ‐ assessment of outcome
All outcomes |
Low risk |
Low |
| Summary assessment |
Unclear risk |
Unclear |
