5 documents found, page 1 of 1
Unmeasured confounding and misclassification in studies estimating vaccine effe...
Humphreys, James; Nicolay, Nathalie; Braeye, Toon; Van Evercooren, Izaak; Holm Hansen, Christian; Moustsen-Helms, Ida Rask; Sacco, ChiaraBackground: Electronic health record (EHR)-based observational studies can rapidly provide real-world data on vaccine effectiveness (VE), though EHR data may be prone to misclassification and unmeasured confounding. Methods: In VEBIS-EHR, a retrospective multi-country COVID-19 VE cohort study, we examined unmeasured confounding using a negative control outcome (death not related to COVID-19) and misclassificati...
Comparison of two methods for the estimation of COVID-19 vaccine effectiveness ...
Monge, Susana; Humphreys, James; Nicolay, Nathalie; Braeye, Toon; Van Evercooren, Izaak; Hansen, Christian Holm; Emborg, Hanne-Dorthe; Fabiani, MassimoWithin an infrastructure to monitor vaccine effectiveness (VE) against hospitalization due to COVID-19 and COVID-19 related deaths from November 2022 to July 2023 in seven countries in real-world conditions (VEBIS network), we compared two approaches: (a) estimating VE of the first, second or third COVID-19 booster doses administered during the autumn of 2022, and (b) estimating VE of the autumn vaccination dos...
Effectiveness of XBB.1.5 Monovalent COVID‐19 Vaccines During a Period of XBB.1....
Monge, Susana; Humphreys, James; Nicolay, Nathalie; Braeye, Toon; Van Evercooren, Izaak; Holm Hansen, Christian; Emborg, Hanne‐Dorthe; Sacco, ChiaraUsing a common protocol across seven countries in the European Union/European Economic Area, we estimated XBB.1.5 monovalent vaccine effectiveness (VE) against COVID-19 hospitalisation and death in booster-eligible ≥ 65-year-olds, during October–November 2023. We linked electronic records to construct retrospective cohorts and used Cox models to estimate adjusted hazard ratios and derive VE. VE for COVID-19 hos...
Relative vaccine effectiveness against COVID-19 hospitalisation in persons aged...
Fontán-Vela, Mario; Kissling, Esther; Nicolay, Nathalie; Braeye, Toon; Van Evercooren, Izaak; Holm Hansen, Christian; Emborg, Hanne-DortheSince 2021, the Vaccine Effectiveness, Burden and Impact Studies of coronavirus disease 2019 (COVID-19) and influenza (VEBIS) project monitors vaccine effectiveness (VE) in real-world conditions to inform vaccination programmes in the European Union/European Economic Area (EU/EEA) countries [1]. One project aims to monitor real-time COVID-19 VE using electronic health registries (EHR) in multiple countries, wit...
Effectiveness of complete primary vaccination against COVID-19 at primary care ...
Kissling, Esther; Hooiveld, Mariëtte; Martínez-Baz, Iván; Mazagatos, Clara; William, Naoma; Vilcu, Ana-Maria; Kooijman, Marjolein N.; Ilić, MajaIntroduction: In July and August 2021, the SARS-CoV-2 Delta variant dominated in Europe. Aim: Using a multicentre test-negative study, we measured COVID-19 vaccine effectiveness (VE) against symptomatic infection. Methods: Individuals with COVID-19 or acute respiratory symptoms at primary care/community level in 10 European countries were tested for SARS-CoV-2. We measured complete primary course overall VE by ...