Comorbidity Risk Factors and Mortality in Patients Hospitalized with Respiratory Syncytial Virus and Influenza A: a Retrospective Observational Cohort Study
Year: 2026
Type: preprint
Study design: Observational Study
Abstract: Purpose: To compare mortality in adults hospitalized with laboratory-confirmed respiratory syncytial virus (RSV) with influenza A and identify comorbidity as risk factors for death. Methods : We performed a retrospective cohort study including adults admitted to a hospital in the Central Denmark Region from February 2019 to February 2024 with a positive RSV or influenza A test. Outcomes were in-hospital, 30-, 90- and 180-day mortality. A cox regression including age, sex and comorbidities was used. Results: The cohort comprised 4,416 patients: 1,366 with RSV and 3,050 with influenza A. Patients with RSV were older (median age 74 vs 67) and more often had at least one comorbidity (76% vs 61%). Mortality was higher for RSV than influenza A across all follow-up periods. Adjusted hazard ratios (aHRs) for mortality were also higher for RSV for all follow up periods. In adjusted 90-day models, shared risk factors for death were chronic obstructive pulmonary disease (COPD) (aHR RSV 1.59, 1.10–2.28; influenza A aHR 1.69, 1.18–2.42) and chronic liver disease (RSV 4.21, 1.54–11.49; influenza A 2.81, 1.23–6.40). In patients with RSV chronic heart disease (aHR 1.46, 1.02–2.09) was also associated with increased risk of death. Asthma showed inverse associations in both models, significant only for RSV (aHR 0.43, 0.19–0.98). Diabetes was not associated with increased risk for any of the patient groups. Conclusions: Among hospitalized adults, RSV was associated with higher mortality than influenza A. Mortality risk factor findings support targeted prevention in older adults and patients with comorbidity.
Source: Research Square
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7204181737