Age, high-risk conditions predict RSV hospitalization in children

Hospitalization due to respiratory syncytial virus (RSV) infection in infants and children is significantly associated with younger age, high-risk conditions, and palivizumab-indicated underlying conditions, according to a study in Japan.

Insurance claims data from 12 municipalities were used to identify RSV cases in children aged ≤2 years between April 2017 and March 2022. The investigators analysed the patients’ characteristics and hospitalization status according to the presence of palivizumab-indicated underlying conditions. They also identified factors associated with hospitalization, length of stay (LOS), and hospital expenditures using regression models.

A total of 1,025 first-time RSV patients were analysed, of whom 860 were infants aged <1 year and 165 were children aged 1–2 years. Among infants, 777 (90.3 percent) were palivizumab-ineligible and 83 (9.7 percent) were palivizumab-eligible. Only 13 (15.7 percent) palivizumab-eligible infants had been administered palivizumab a month prior to RSV infection, and eight required hospitalization.

The following factors significantly correlated with RSV hospitalization: age (odds ratio [OR], 0.84, 95 percent confidence interval [CI], 0.79–0.88), palivizumab-indicated underlying conditions (OR, 1.82, 95 percent CI, 1.13–2.89), and nonindicated high-risk conditions (OR, 4.87, 95 percent CI, 2.28–10.99). The same factors also correlated with LOS. On the other hand, hospital expenditures were significantly associated with age, high-risk conditions, and LOS.

“Most hospitalized patients did not receive palivizumab in the month before RSV infection despite being eligible, suggesting that some hospitalizations were preventable through appropriate palivizumab use,” the investigators said.