Early bedside risk stratification using Charlson comorbidity index and NEWS2 in adults hospitalized with respiratory syncytial virus infection: a multicentre cohort study.

Respiratory syncytial virus (RSV) causes severe respiratory infections in elderly or immunocompromised adults, leading to substantial hospital burden during winter epidemics. While several studies have identified prognostic factors for RSV infection, it remains unclear which bedside clinical scores best predict short-term mortality and hospitalization burden in adults with RSV infection. We conducted a retrospective, multicentre study including adults (> 18 years) who presented to emergency departments or were hospitalized in three Parisian hospitals between October 1, 2022 and September 30, 2023, with RSV A/B infection confirmed by multiplex PCR. Multivariable logistic regression models were used to identify factors associated with 30-day mortality and prolonged hospitalization (length of stay ≥ 7 days). Among 268 included patients, median age was 73 years (IQR, 55.7-86.0), and 58% had severe multimorbidity defined by a Charlson Comorbidity Index (CCI) ≥ 5. Thirty-day overall mortality was 10.1%. Of 226 hospitalized patients, 135 (59.7%) had prolonged stays and 36 (16%) required intensive care. Thirty-day mortality was independently associated with NEWS2 score ≥ 5 and CCI ≥ 5 with a model demonstrating good discrimination (AUC 0.82). CCI ≥ 5 and bacterial superinfection were independently associated with prolonged hospitalization. Assessment of both clinical severity and multimorbidity using simple bedside scores may help identify adults with RSV at higher risk of prolonged hospitalization and short-term mortality. These patients could eventually benefit from RSV vaccination or early specific antiviral treatment.