The Societal and Indirect Economic Burden of Seasonal Influenza in the United Kingdom.

Seasonal influenza is a significant public-health issue. In the UK, the influenza season is associated with an increased demand for and pressure on the NHS. The direct health and economic impacts of seasonal influenza have received much attention. However, less attention has been given to its broader societal burden, including its indirect economic impact. We first conducted a rapid evidence assessment of the literature to understand the societal burden of seasonal influenza in the UK. Secondly, we conducted analyses of publicly available, aggregated data from NHS England and NHS Digital to better understand the impact of seasonal influenza on the provision of NHS services both before and after the COVID-19 pandemic. We also conducted a geographically representative survey of 1,000 working-age adults across the UK, who reported having influenza or caring for a dependent with influenza during at least one of the past four influenza seasons to understand impacts related to absenteeism and presenteeism in the workplace, lost wages and out-of-pocket costs. Fourthly, we conducted interviews with 20 key stakeholders within the NHS from primary care and secondary care across the four UK nations. Lastly, we used an epidemiologic-economic framework to estimate the number of influenza cases and then applied a macro-economic computable general equilibrium model to estimate the indirect economic costs associated with lost economic productivity among working-age adults who become ill with influenza.