Hospitalisation and healthcare burden of respiratory syncytial virus in adults aged 50 years and older in France, 2015–2022

BACKGROUND: Respiratory Syncytial Virus (RSV) can cause severe illness in adults, leading to respiratory and non-respiratory complications, functional decline, hospitalisation, and death. OBJECTIVES: This study describes French patients aged ≥50 years hospitalised with RSV (2015-2022) and their care pathways, including hospitalisation and outpatient healthcare use and costs. METHODS: Data were extracted from the French National Health Data System (SNDS). Patients were classified into four risk groups (high: immunocompromised; medium: underlying predisposition; other; no comorbidities) and four age groups (50-59, 60-64, 65-74, ≥75 years). Healthcare use (laboratory tests, imaging, pharmacy, GP visits, rehospitalisations) and costs were analysed across three periods: 60-30 days pre-hospitalisation (reference period), index hospitalisation, and 30 days post-hospitalisation. RESULTS: We identified 15,509 RSV-related hospitalisations for 15,169 adults ≥50 years. Median age was 80 years, with age ≥75 years comprising 61.7% of the cohort. 15.9% were high risk, 71.4% medium risk, 4.8% other, and 7.8% had no comorbidities. Intensive care was required in 25.4% of cases. In-hospital mortality was 8.5%, with an additional 3.8% dying within 30 days post-discharge. Rehospitalisation occurred in 17.8% of patients, nearly half for cardiorespiratory causes. Median index hospitalisation cost was €4,252 (Q1; Q3: €3,077; €7,007), and post-hospitalisation costs increased across all ages and risk profiles compared to the reference period. CONCLUSION: RSV imposes a substantial hospitalisation and cost burden in adults ≥50 years, especially older patients and those with comorbidities. Expanded preventive vaccination strategies could help reduce this impact.