Secondary healthcare resource utilization and related costs associated with influenza-related hospital admissions in adult patients, England 2016 - 2020.

Introduction: This study aims to investigate healthcare resource utilization and related costs for influenza virus infections in adults admitted into secondary care in England across four influenza seasons.

Methods: This study includes all influenza admissions from the Hospital Episode Statistics database (HES) across England, September 2016 to March 2020. Descriptive analyses and comparative modeling techniques were used to assess the impact of influenza on risk groups of interest.

Results: Influenza admissions were estimated to cost £401 M. Average admission costs were heavily impacted by age and comorbid status, with comorbid patients representing 91% of costs. Additionally, patients with comorbidities treated in secondary care cost twice as much as non-comorbid patients, after adjusting for age and gender. Comorbid patients also had increased length of stay (LOS) and admissions to ICU, with patients' LOS being a core contributing factor to higher costs.

Conclusion: The study documents the substantial burden of influenza in England, emphasizing the impact of age and comorbid status on healthcare resource utilization (HCRU) and related costs. The data presented offers critical information to healthcare systems evaluating new strategies to alleviate the winter pressures on the NHS; highlighting the need to implement vaccination campaigns with enhanced vaccinations and increased vaccine coverage.