PhD defence M. (Maryam) Darvishian: Real-world influenza vaccine effectiveness
|When:||Tu 21-06-2016 at 11:00|
New designs and methods to adjust for confounding and bias
As recommended by the World Health Organization, seasonal influenza vaccination of high-risk populations (e.g. elderly and individuals with specific chronic medical conditions) is the main preventive strategy against influenza and influenza-related complications. Despite these recommendations, influenza vaccination coverage rates are still generally low which partly could be due to uncertainties about the real-world effectiveness of seasonal influenza vaccine. Limitations in conducting experimental randomized (placebo-) controlled trials as well as susceptibility of observational study designs to different sources of bias contribute to this on-going uncertainty.
In this thesis we therefore aimed to estimate seasonal influenza vaccine effectiveness (IVE) by means of new study designs and methods to provide more accurate IVE estimates while addressing and/or adjusting for the potential biases and confounders. We found that even after adjusting for different sources of bias and potential confounders, influenza vaccine is moderately effective against influenza and influenza related-complications among elderly population.
Furthermore, we observed that conventional meta-analysis methods might not provide the best tool to measure pooled IVE estimates and more accurate methods should be considered in future studies. Finally, we observed extreme variability in IVE estimates depending on influenza virus (sub)types, influenza season, and the type of control group that is included in the test-negative design case-control study.
|Promotors:||prof. dr. E. (Eelko) Hak, E.R. van den Heuvel|