Aims and objectives: Respiratory syncytial virus (RSV) can cause serious illnesses, particularly among older adults and those with comorbidities. Yet, RSV incidence in adults is underestimated, largely due to infrequent testing. We estimated RSV-attributable population-based incidence in adults with and without selected risk factors in Germany using a retrospective statistical model-based approach.

Methods: Data were obtained from a Statutory Health Insurance database for 2015-2019. A quasi-Poisson regression model was fitted to estimate RSV-attributable incidence of respiratory hospitalizations and primary care visits (overall and stratified by age group and risk status). The model accounted for baseline seasonal variation throughout the year and incorporated hospitalizations for RSV in children <2 years and influenza in adults ?60 years as viral circulation proxies.

Results: Incidence of RSV-attributable hospitalizations was higher among older adults and adults with risk factors (Table). Data on primary care visits will be presented at the conference.

Conclusion: Addressing the underestimation of RSV hospitalization incidence in Germany, the use of a model-based approach showed estimates comparable to a recent global meta-analysis of prospective studies (adults ?65 years: 157?347/100,000; Li et al. 2023). Incidence was higher in older adults and those with risk factors.