Insights into the protective effects of influenza vaccination: More hospitalizations but lower follow-up mortality during the 2014/15 influenza season in a Swiss cohort

摘要

Background: Observational studies of influenza vaccination are criticized as flawed due to unmeasured confounding. The goal of this cohort study was to explore the value and role of secondary claims data to inform the effectiveness of influenza vaccination, while systematically trying to reduce potential bias.