Abstract
Objective In 2014, the American Academy of Pediatrics (AAP) changed its policy on the use of
respiratory syncytial virus immunoprophylaxis (RSV-IP) so that RSV-IP was no longer
recommended for use among infants without other medical conditions born >29 weeks
of gestational age (wGA). This study examines 10-year trends in RSV-IP and RSV hospitalizations
among term infants and preterm infants born at 29 to 34 wGA, including the 5 RSV seasons
before and 5 RSV seasons after the AAP guidance change.
Study Design A retrospective observational cohort study of a convenience sample of infants less
than 6 months of age during RSV season (November–March) born between July 1, 2008,
and June 30, 2019, who were born at 29 to 34 wGA (preterm) or >37 wGA (term) in the
IBM MarketScan Commercial and Multi-State Medicaid databases. We excluded infants
with medical conditions that would independently qualify them for RSV-IP. We identified
RSV-IP utilization along with RSV and all-cause bronchiolitis hospitalizations during
each RSV season. A difference-in-difference model was used to determine if there was
a significant change in the relative rate of RSV hospitalizations following the 2014
policy change.
Results There were 53,535 commercially insured and 85,099 Medicaid-insured qualifying preterm
infants and 1,111,670 commercially insured and 1,492,943 Medicaid-insured qualifying
term infants. Following the 2014 policy change, RSV-IP utilization decreased for all
infants, while hospitalization rates tended to increase for preterm infants. Rate
ratios comparing preterm to term infants also increased. The relative rate for RSV
hospitalization for infants born at 29 to 34 wGA increased significantly for both
commercially and Medicaid-insured infants (1.95, 95% CI: 1.67–2.27, p <0.001; 1.70, 95% CI: 1.55–1.86, p <0.001, respectively). Findings were similar for all-cause bronchiolitis hospitalizations.
Conclusion We found that the previously identified increase in RSV hospitalization rates among
infants born at 29 to 34 wGA persisted for at least 5 years following the policy change.
Key Points
-
Immunoprophylaxis rates decreased after the 2014 American Academy of Pediatrics guidelines
update.
-
Rate of RSV hospitalization increased among preterm infants after the 2014 AAP guidelines
update.
-
Increase in RSV hospitalization persisted for at least 5 years after AAP guidelines
update.
Keywords
respiratory system - respiratory syncytial virus - preterm infants - hospitalization
