Cost of RSV Hospitalization Could Decrease if Treatment Targets Children Younger Than 3 Months

The reduction in post–COVID-19 costs for hospitalizations for respiratory syncytial virus (RSV) for infants 3 months and younger outweighed the cost increase for children aged 3 to 24 months, making temporal immunization a primary objective in decreasing costs for RSV hospitalizations (RSVH), according to new study findings published in Vaccine.

RSV is the leading cause of lower respiratory tract infections in infants worldwide and the leading cause of hospital admissions in children younger than 1 year. In France, the RSV epidemic resulted in a mean 42,225 RSV-related hospitalizations in children 5 years and younger per season from 2010 to 2018. Transmission of RSV has been affected by nonpharmaceutical interventions that were implemented during the COVID-19 pandemic. The present study aimed to “estimate the impact of age distribution, clinical severity, and the incidence of RSVH on hospitalization costs stratified by age group between pre–COVID-19 seasons and the 2020/2021 RSV season.”

Data for the study came from 4 cohorts from 3 public hospitals in Lyon whose data. The data were collected retrospectively from 2013/2015, 2014/2016, 2015/2017, and 2019/2021. Data from a previous study reporting on 2014-2017 in children younger than 12 months were included alongside data on children aged 12 to 24 months. Cases from September to May of the following year were defined as being in the RSV season for the 2014/2015, 2015/2016, and 2016/2017 pre–COVID-19 seasons. Cases between December and the end of August of the following year were included for the 2020/2021 season.

An RSV case was defined as any child with a confirmed care of RSV who was hospitalized during the RSV season in the first 2 years of their life during the study period. Characteristics for all children were extracted. All costs were adjusted to the value of the 2021 euro.

The cohorts ranged from 18,076 to 18,317 births for the 2014/2015 to 2016/2017 seasons, and the 2020/2021 season included 17,561 births. The median (IQR) age of children hospitalized was lower in the 2014/2017 season (2.2 [1.1-4.8] months) compared with the 2020/2021 season (3.3 [1.7-8.0] months).

A decrease in incidence rate was found in children younger than 3 months in the 2020/2021 season compared with the pre–COVID-19 period, respectively (4.6; 95% CI, 4.1-5.2 vs 3.1; 95% CI, 2.4-4.0) per 1000 person-months. There were also significant increases found in children aged 3 to 24 months (0.48; 95% CI, 0.41-0.56 vs 0.66; 95% CI, 0.52-0.84) and in the incidence rate in 2020/2021 compared with pre–COVID-19 period in children aged 6 to 24 months (0.30; 95% CI, 0.24-0.37 vs 0.46; 95% CI, 0.33-0.62).

The median cost for RSVH per child in those younger than 3 months was €2955 (US $3170.30), which was higher than the €2907 (US $3118.80) seen in children aged 3 to 24 months; this extended to the 2020/2021 season, where costs for children younger than 3 months were €3363 (US $3606.45) compared with €2389 (US $2561.94) for children aged 3 to 24 months. A lower median length of stay was also found in children aged younger than 3 months in both the pre– and post–COVID-19 periods.

Preterm infants had a higher median RSVH cost (€3479 [US $3730.84]) in the pre–COVID-19 period compared with during COVID-19 (€4137 [US $4436.48]) during COVID-19 period) and with full-term infants in both periods (€2934 [US $3146.39] and €2537 [US $2720.65], respectively).

The total cost of RSVH decreased by 41.6%, or €191,428 (US $205,285.47), in children younger than 3 months in the 2020/2021 RSV season compared with the mean total costs per season before COVID-19. Total costs of RSVH decreased by 31.0%, or €201,770 (US $216,376.13), in the 2020/2021 season regardless of age.

Potential limitations on these study findings are that RSV seasons from 2017 to 2020 were not assessed for this study and RSV subtype could have been associated with less severe clinical disease in the 2020/2021 season. Further, behavior in seeking health care may have been changed due to the pandemic and an increase in outpatient costs could not be excluded.

The researchers concluded that the reduction of total seasonal hospitalization costs was linked to the increase in the median age of children requiring RSVH and the decrease in incidence in the youngest infants.

Reference

Roy A, Polazzi S, Ploin D, et al; VRS study group in Lyon. The increasing age of respiratory syncytial virus-related hospitalisation during COVID-19 pandemic in Lyon was associated with reduced hospitalisation costs. Vaccine. Published online May 10, 2023. doi:10.1016/j.vaccine.2023.05.021