Marleen Bokern

Jan 6, 2025 | onlinelibrary.wiley.com | Marleen Bokern |Christopher T. Rentsch |Jennifer K Quint |Jacob N. Hunnicutt

COVID-19 outcomes may have been at risk of misclassification early during the COVID-19 pandemic. No pharmacoepidemiological studies have evaluated the impact of such misclassification on their findings. We used several forms of quantitative bias analysis to adjust for outcome misclassification in an analysis of inhaled corticosteroids and COVID-19 hospitalisation and death. We found that all methods shifted effect estimates away from the null, albeit to a limited extent.

Aug 14, 2024 | medrxiv.org | Marleen Bokern |Christopher T. Rentsch |Jennifer K Quint |Jacob N. Hunnicutt

MPB is funded by a GSK PhD studentship to investigate the application of quantitative bias analysis in observational studies of COVID-19. IJD has unrestricted grants from and shares in GSK. AS is employed by LSHTM on a fellowship funded by GSK. JH was employed by GSK and owned stock in GSK during the conduct of this work. CTR and JQ report no conflicts of interest.

Jun 13, 2023 | onlinelibrary.wiley.com | John Tazare |Daniel C. Gibbons |GSK London |Marleen Bokern

Abstract Purpose Prevalent new user (PNU) designs extend the active comparator new user design by allowing for the inclusion of initiators of the study drug who were previously on a comparator treatment. We performed a literature review summarising current practice. Methods PubMed was searched for studies applying the PNU design since its proposal in 2017. The review focused on three components. Firstly, we extracted information on the overall study design, including the database used.