OBJECTIVES: Most infants are infected with respiratory syncytial virus (RSV) before age two, with varying severity. Estimating the true disease burden is complex, as most RSV infections are coded under unspecified respiratory tract infections (RTI) or bronchiolitis. This study aimed to estimate the respiratory related primary and secondary health care resource utilisation (HCRU) and corresponding costs of RSV admissions before age two, in England.

METHODS: This retrospective cohort study used Clinical Practice Research Datalink (CPRD)-Hospital Episode Statistics (HES) linked data to establish a birth cohort of all infants born between 01/03/2015 and 28/02/2017 (n=449,591). Case cohorts included infants under two with a hospital admission of: 1) RSV (n=4,813), 2) bronchiolitis (n=22,913), 3) any RTI (n=56,871). Each case cohort was compared with all birth cohort infants without the corresponding admission (comparative cohorts). Respiratory related HCRU (primary care, outpatient, accident and emergency [A&E], and inpatient admissions) and costs were estimated in the month prior to and up to 24 months following the first admission in each cohort, using descriptive analysis.

RESULTS: The RSV-coded cohort had the highest HCRU overall, mean (SD) of 5.1 (4.8) admissions vs. 1.5 (2.4) in its comparative cohort (71% difference). This difference was largely due to A&E and inpatient admissions. Comparable results were found for bronchiolitis-coded and RTI-coded cohorts. Costs were highest in the RSV-coded cohort (£4060 vs. £242 per infant, 94% difference). Costs per infant were lower in the bronchiolitis- and RTI-coded cohorts (£2806, £2038, respectively), but still higher than their comparative cohorts (£177, £87, respectively). Inpatient admissions explained the differences in costs between cases and comparative cohorts.

CONCLUSIONS: Infants with an RSV admission had higher HCRU than infants without an RSV-coded admission, representing a 17-fold higher cost per infant. Given this high burden of RSV infection and the absence of treatment, prevention strategies such as passive immunisation, should be emphasised.