Economic Burden of Influenza and COVID-19 in French Hospitals: Analysis of PMSI Data From 2018 to 2022

OBJECTIVES: COVID-19 significantly impacted the French healthcare system, leading to hospital saturation at pandemic’s peak. While influenza was almost absent during lockdowns, both viruses now co-circulate. This study aims to characterize hospitalizations associated with influenza and COVID-19 in France in 2018-2022 and estimate their related costs.

METHODS: A retrospective, descriptive study was conducted using the French hospital medico-administrative database (PMSI-MCO). Hospitalizations with influenza and/or COVID-19 between July 2018 and December 2022, identified by ICD-10 codes, were included. Analyses were performed by year, month and by age group.

RESULTS: Over the study period, 814,534 COVID-19 and 102,266 influenza hospitalizations were identified. COVID-19 patients were older with a mean (+/- standard deviation) age of 65.8 (+/- 21.7) years (vs 47.2 (+/- 34.4) years for influenza). The proportion of hospitalizations among adults ≥65 years old was greater for COVID-19 (59,5%; 484,998 hospitalizations) compared to influenza (43.5%; 44,519 hospitalizations). Among patients aged ≥65 years, ICU stays were more frequent (21.2% vs 13.6%) and longer (15.3 days vs. 7.7 days) for COVID-19 than for influenza. Overall, costs related to COVID-19 hospitalizations were higher with a mean cost of €6,134 (vs €3,225 for influenza). Peak costs were observed among patients aged 65-75 years (€8,416 for COVID-19; €4,601 for influenza). From October to December 2022 (post-pandemic Omicron variant period), COVID-19 hospitalizations tripled influenza hospitalizations (44,714 vs. 15,262). During this period, COVID-19 stays were longer (9.3 days vs. 6.0 days) and more expensive (€4,719 vs €3,277) than influenza stays among patients aged ≥65 years.

CONCLUSIONS: COVID-19 was associated with a heavier economic burden than influenza in terms of the number of hospital admissions, length of stay, and overall costs, even in late 2022. These findings emphasize the importance of COVID-19 vaccination campaigns in France and the need to improve vaccination coverage, particularly for older adults.