The outpatient economic burden of respiratory syncytial virus infection in adults aged ≥ 60 years in Germany: results from the BUCOSS study

Abstract Background Respiratory syncytial virus (RSV) is a major cause of acute respiratory infection (ARI) in adults aged ≥ 60 years, but data on its outpatient epidemiology and societal costs remain limited. Methods BUCOSS was a prospective observational study conducted over 3 seasons (2022/23–2024/25) in adults aged ≥ 60 years presenting with ARI to 29 outpatient practices in Germany. Multiplex PCR testing was performed at baseline. RSV-positive patients were prospectively followed for up to 28 days. Clinical and socioeconomic burden, including direct medical, indirect, and patient-borne out-of-pocket costs, was assessed using structured questionnaires on days 0, 14, and 28. Approximate national burden was estimated using incidence-based and ARE–prevalence-based extrapolation, including an additional scenario analysis excluding indirect costs. Results Among 3,261 patients with ARI, 192 (5.9%) had PCR-confirmed RSV infection. RSV prevalence was 5.49%, and estimated RSV incidence was 1,030.6 cases per 100,000 population. After exclusion of 4 patients hospitalized at baseline, 188 patients were included in the outpatient cost analysis. Mean age was 71.6 (SD 8.52) years, 57.4% were female, and 60.1% met the study high-risk criteria. Mean societal cost per episode was €510.0 (SD €742.58); costs were highest in patients aged 60–64 years. Total costs comprised direct medical costs of €161.3 (SD €59.57), indirect costs of €331.8 (SD €746.75), and out-of-pocket costs of €16.9 (SD €22.25), corresponding to 31.6%, 65.1%, and 3.3% of total societal costs, respectively. Indirect costs were driven almost entirely by productivity losses. Approximately 40% of cases occurred in adults without study-defined high-risk status. The two extrapolation approaches yielded approximate estimates of 258,000–374,000 medically attended outpatient RSV cases per season among adults aged ≥ 60 years in Germany, corresponding to €131.7–190.9 million in societal costs. In a scenario analysis excluding indirect costs, the estimated burden decreased to €46.0–66.7 million per season. Conclusions RSV is an economically important cause of outpatient ARI in older adults. These findings highlight a substantial outpatient burden beyond inpatient care and support RSV prevention strategies in aging populations.