COMPARATIVE SEVERITY OF COVID-19, INFLUENZA, AND RSV HOSPITALIZATIONS IN FRANCE: A PROPENSITY SCORE ANALYSIS USING NATIONAL HOSPITAL DATA
Author(s)
Liem Binh Luong, MD1, Nicolas Capit2, Laureen Majed, PhD3, Aleksandra Anchim, PharmD3, Ellina Degand, PharmD3, Clélia Bignon-Favary, MSc4, Christelle Ferreira, MSc4, Sophie LARRIEU, PhD4, Yvanie Caillé, MSc5, Marie Lachâtre, MD1, Slim Fourati, MD6.
1Hôpital Cochin, Assistance Publique – Hôpitaux de Paris, Paris, France, 2RWE Manager, AstraZeneca, Courbevoie, France, 3AstraZeneca, Courbevoie, France, 4HORIANA, BORDEAUX, France, 5Renaloo, Paris, France, 6Groupe Hospitalier Henri Mondor, Assistance Publique – Hopitaux de Paris, Créteil, France.
1Hôpital Cochin, Assistance Publique – Hôpitaux de Paris, Paris, France, 2RWE Manager, AstraZeneca, Courbevoie, France, 3AstraZeneca, Courbevoie, France, 4HORIANA, BORDEAUX, France, 5Renaloo, Paris, France, 6Groupe Hospitalier Henri Mondor, Assistance Publique – Hopitaux de Paris, Créteil, France.
OBJECTIVES: To compare the severity of COVID-19, influenza, and respiratory syncytial virus (RSV) hospitalizations in France during the 2022-2023 epidemiological season after adjusting for patient-level confounders.
METHODS: A retrospective cohort study was conducted using the French national hospital claims database (Programme de Médicalisation des Systèmes d'Information, PMSI). Patients aged ≥2 years hospitalized with a primary diagnosis of COVID-19, influenza, or RSV between July 2022 and June 2023 were included. Hospitalizations coding multiple viruses or subsequent stays for the same episode were excluded. Propensity score analysis using multinomial logistic regression with overlap weighting was applied to maximize covariate balance and mitigate extreme weights. Covariates included age, sex, region, origin of hospitalization, season, immunodepression status, and comorbidities. Severity outcomes were in-hospital mortality and intensive care unit (ICU) admission. Risk ratios (RR) with 95% confidence intervals were estimated using bootstrap resampling (1,000 replicates). Sensitivity analyses used inverse probability of treatment weighting (IPTW) and covariate balancing propensity score (CBPS).
RESULTS: After exclusions, 140,999 hospitalizations were analyzed (101,141 COVID-19; 31,377 influenza; 8,481 RSV). Overlap weighting achieved excellent covariate balance (all standardized mean differences <0.1). Weighted in-hospital mortality was 8.38% for COVID-19, 5.50% for RSV, and 5.26% for influenza. COVID-19 mortality was significantly higher than RSV (RR 1.52; 95%CI 1.39-1.68) and influenza (RR 1.59; 95%CI 1.50-1.70), while RSV and influenza did not differ significantly (RR 0.96; 95%CI 0.86-1.07). Weighted ICU admission rates were comparable: COVID-19 9.60%, RSV 10.32%, influenza 9.96%, with no statistically significant differences between viruses. Sensitivity analyses using IPTW and CBPS confirmed these findings.
CONCLUSIONS: After adjusting for confounders, COVID-19 was associated with significantly higher in-hospital mortality than RSV and influenza, while ICU admission rates were similar across the three viruses. RSV and influenza demonstrated comparable severity profiles. These findings support tailored prevention strategies and resource planning for major respiratory viral infections.
METHODS: A retrospective cohort study was conducted using the French national hospital claims database (Programme de Médicalisation des Systèmes d'Information, PMSI). Patients aged ≥2 years hospitalized with a primary diagnosis of COVID-19, influenza, or RSV between July 2022 and June 2023 were included. Hospitalizations coding multiple viruses or subsequent stays for the same episode were excluded. Propensity score analysis using multinomial logistic regression with overlap weighting was applied to maximize covariate balance and mitigate extreme weights. Covariates included age, sex, region, origin of hospitalization, season, immunodepression status, and comorbidities. Severity outcomes were in-hospital mortality and intensive care unit (ICU) admission. Risk ratios (RR) with 95% confidence intervals were estimated using bootstrap resampling (1,000 replicates). Sensitivity analyses used inverse probability of treatment weighting (IPTW) and covariate balancing propensity score (CBPS).
RESULTS: After exclusions, 140,999 hospitalizations were analyzed (101,141 COVID-19; 31,377 influenza; 8,481 RSV). Overlap weighting achieved excellent covariate balance (all standardized mean differences <0.1). Weighted in-hospital mortality was 8.38% for COVID-19, 5.50% for RSV, and 5.26% for influenza. COVID-19 mortality was significantly higher than RSV (RR 1.52; 95%CI 1.39-1.68) and influenza (RR 1.59; 95%CI 1.50-1.70), while RSV and influenza did not differ significantly (RR 0.96; 95%CI 0.86-1.07). Weighted ICU admission rates were comparable: COVID-19 9.60%, RSV 10.32%, influenza 9.96%, with no statistically significant differences between viruses. Sensitivity analyses using IPTW and CBPS confirmed these findings.
CONCLUSIONS: After adjusting for confounders, COVID-19 was associated with significantly higher in-hospital mortality than RSV and influenza, while ICU admission rates were similar across the three viruses. RSV and influenza demonstrated comparable severity profiles. These findings support tailored prevention strategies and resource planning for major respiratory viral infections.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EPH11
Topic
Clinical Outcomes, Epidemiology & Public Health, Study Approaches
Topic Subcategory
Public Health
Disease
Infectious Disease (non-vaccine)