Background and Aim Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection (LRTI) in infants and young children and the leading cause of severe bronchiolitis between October to March. The burden of RSV hospital admissions on the NHS is unclear. Our aim was to estimate the number of RSV occupied bed days (OBDs) in the NHS in infants ≤ 18 months of age across 4 RSV seasons (2007/2008 to 2010/2011).

Methods A retrospective analysis of hospital admissions was performed using the Caspe Healthcare Knowledge System (CHKS) database which contains patient data from Hospital Episode Statistics (HES) as well as data collected directly from hospital trusts in England. All LRTI admissions with a definitive (confirmed) RSV code were identified. In addition there were LRTI hospital admissions which were unspecified but probably due to RSV based on season, age and diagnostic codes determined by an expert panel. To further increase the chances that the unspecified LRTI admissions were due to RSV and to minimise confounding by influenza, the analysis was limited to a narrower RSV season defined as 70% spread of confirmed RSV admissions around the peak week of RSV admissions. Details of all RSV admissions (confirmed and probable) were extracted from the database and analysed to determine number of RSV OBDs.

Results Number of confirmed RSV OBDs increased from 37,395 in 2007/08 to 54,384 in 2010/11 with the corresponding rise in the estimated “true” burden of RSV OBDs. We also observed an increase in the total (confirmed and probable) RSV admissions during the same period.

Conclusions This study increases our understanding of the burden of paediatric RSV hospitalisations on the NHS England. There is an opportunity to reduce this burden by the implementation of better RSV prevention strategies.