Healthcare resource utilization and cost burden of COVID-19 according to vaccination status in adults in Ontario, Canada, 2021–2023

AIMS: This study aims to describe healthcare resource utilization (HCRU) and cost burden associated with COVID-19 cases in Ontario, Canada, and assess variations by vaccination status. METHODS: We conducted a population-based retrospective cohort study using administrative health data from Ontario, focusing on COVID-19 cases from January 1, 2021, to May 31, 2023. Cases were identified by their first positive PCR test, and their healthcare interactions were followed for up to 12 months post-infection. All-cause HCRU and direct healthcare cost were compared before and after infection using generalized linear models. RESULTS: Data from a total of 1,321,174 COVID-19 cases were analyzed, with 87% having at least one healthcare interaction in the year preceding their infection. All-cause HCRU increased post-infection, with the greatest rise observed in the first month, largely attributable to hospitalizations (Mean [SD] hospitalizations per person per month [PPPM] at Month 1 vs. Look-back: 1.1 [0.3] vs. 0.1 [0.1], p < .0001) and ICU admissions (mean [SD] admissions PPPM at Month 1 vs. Look-back: 1.0 [0.1] vs. 0.1 [0.0], p < .0001). The healthcare cost per person rose in both the six and twelve months pre- versus post-infection. This increase is primarily attributable to ICU admission, hospitalization, and mechanical ventilation costs. On average, vaccinated individuals exhibited smaller increases in ICU costs (vaccinated: + CAD 5,838 to CAD 18,730 vs. unvaccinated: + CAD 24,597) and hospitalization costs (vaccinated: + CAD 623 to CAD 5,201 vs. unvaccinated: + CAD 9,072) six months post-infection compared to unvaccinated cases. CONCLUSIONS: Data from this study cohort suggests that COVID-19 strains healthcare resources, namely as a result of hospitalization and mechanical ventilation. Vaccinated individuals demonstrated a reduced burden compared to their unvaccinated counterparts. These findings underscore the importance of vaccination in reducing severe outcomes and healthcare costs, providing insights for public health strategies and individual patient counseling.