Impact of Vaccination on Cost and Course of Hospitalization Associated with COVID-19 Infection

Selina T Somani; Rachelle L Firestone; Monica A Donnelley; Luciano Sanchez; Chad Hatfield; Jeffrey Fine; Machelle D Wilson; Jeremiah J Duby

doi:10.1017/ash.2022.364

Impact of Vaccination on Cost and Course of Hospitalization Associated with COVID-19 Infection

Antimicrob Steward Healthc Epidemiol. 2023 Jan 25;3(1):e19. doi: 10.1017/ash.2022.364. eCollection 2023.

Authors

Selina T Somani¹, Rachelle L Firestone¹, Monica A Donnelley¹, Luciano Sanchez¹, Chad Hatfield¹, Jeffrey Fine², Machelle D Wilson², Jeremiah J Duby¹

Affiliations

¹ Department of Pharmacy, University of California Davis Health, Sacramento, California.
² Division of Biostatistics, University of California Davis, Sacramento, California.

Abstract

Objective: Examine the impact of vaccination status on hospital cost and course for patients admitted with COVID-19 infection.

Design: Retrospective cohort study characterizing vaccinated and unvaccinated individuals hospitalized for COVID-19 between April 2021 to January 2022.

Setting: Large academic medical center.

Methods: Patients were included if they were greater than 18 years old, fully vaccinated or unvaccinated against COVID-19, and admitted for COVID-19 infection.

Patients: 437 consecutively admitted patients for COVID-19 infection met inclusion criteria. Of these, 79 were excluded for unknown or partial vaccination status, transfer from an outside hospital, or multiple COVID-19 related admissions.

Results: Overall, 279 (77.9%) unvaccinated patients compared to 79 (22.1%) vaccinated patients were hospitalized with a diagnosis of COVID-19. Average length of stay was significantly lower in the vaccinated group (6.47 days versus 8.92 days, P = 0.03). Vaccinated patients experienced a 70.6% lower risk of ICU admission (OR = 0.29, 95% CI 0.12-0.71, P = 0.006). The unadjusted cost of hospitalization was not found to be statistically significant ($119,630 versus $191,146, P = 0.06). After adjusting for age and comorbidities, vaccinated patients experienced a 26% lower cost of hospitalization compared to unvaccinated patients (P = 0.004). Unvaccinated patients incurred a significantly higher cost of hospitalization per day ($29,425 vs $13,845 P < 0.0001). Unvaccinated patients (n = 118, 42.9%) were more likely than vaccinated patients (n = 16, 20.3%) to require high-flow oxygen or mechanical ventilation (OR = 2.95, 95% CI 1.62-5.38, P = 0.0004).

Conclusion: Vaccinated patients experienced a lower cost of hospitalization after adjusting for age and comorbidities and shorter length of stay compared to unvaccinated patients admitted for COVID-19.

Keywords: COVID-19; cost; hospital length of stay; vaccination.