Modeling the value of an emergency department influenza vaccination program

Background

Seasonal influenza continues to present a significant annual burden as the vaccination rate in the United States is 51.8%. Emergency Department (ED) based influenza programs have been successfully implemented and improve vaccine uptake, reduce incidence and costs, and improve outcomes.

Objective

To develop a predictive model to assess preventable influenza cases, hospitalizations, fatalities, and incremental cost avoidance based on the unvaccinated population.

Methods

A retrospective cohort of ED encounters limited to Medicare and Medicaid populations was performed across 14 tertiary care hospital EDs and six freestanding EDs for 2020. The total number of unvaccinated individuals was identified to determine the potential impact of an ED vaccination campaign. The average cost and loss per inpatient stay was identified from prior industry Medicare benchmark data and was utilized to extrapolate Medicaid losses. Results from published cost-effectiveness studies identified the vaccination thresholds to prevent one additional case of influenza, one additional hospitalization, and one additional fatality.

Results

A total of 39,463 unvaccinated individuals were identified, with 14,064 classified as Medicare, and 25,379 classified as Medicaid. Assuming a 95% target outreach, 90% medical eligibility, and 70% acceptance rate, 414 influenza cases would be prevented (266 Medicaid, 148 Medicare), 28 hospitalizations would be prevented (18 Medicaid, 10 Medicare), and eight deaths would be prevented (5 Medicaid, 3 Medicare). Accordingly, a reduction in admissions would prevent $409,360 in total inpatient medical costs and $36,232 in losses to healthcare systems.

Conclusion

An ED-based influenza vaccination program would have a measurable impact on patient influenza disease burden and associated medical expenditures.