Association Between Updated Guideline-Based Palivizumab Administration and Hospitalizations for Respiratory Syncytial Virus Infections.

Background: Since its introduction, palivizumab has been used to prevent respiratory syncytial virus (RSV) infection in high-risk populations. Recommendations for palivizumab administration changed in 2014. We examined whether adherence to 2014 palivizumab guidelines affected RSV hospitalization rates.

Methods: This was a retrospective sequential period analysis comparing the incidence of RSV hospitalization in patients younger than 2 years of age before and after implementation of 2014 palivizumab use criteria. Hospitalization data were prospectively collected through age-based surveillance for the post-2014 guideline period (November 1, 2014 to April 1, 2015 RSV season). Comparative data were collected retrospectively for hospitalizations during the pre-2014 guideline period of 2 previous RSV seasons (November 1, 2012 to April 1, 2013 and November 1, 2013 to April 1, 2014). The primary outcome was RSV hospitalization rate, and number of palivizumab doses administered was analyzed as a secondary outcome.

Results: During the study period, 194 RSV hospitalizations occurred. The rate of RSV hospitalization was 5.37 per 1000 children <24 months in the pre-2014 guideline period versus 5.78 per 1000 children <24 months in the post-2014 guideline period (difference of +0.4, 95% confidence interval: -1.2 to +2, P = 0.622). During the pre-2014 guideline period, 21.7 doses per 1000 children <24 months of palivizumab were administered, which decreased to 10.3 doses per 1000 children <24 months in the post-2014 guideline period, yielding a reduction of 11.4 doses per 1000 children <24 months (95% confidence interval: 14.3-8.4, P < 0.001).

Conclusions: The implementation of 2014 palivizumab use criteria was not associated with an increased incidence of RSV hospitalization for children younger than 2 years of age but was associated with significantly less use of palivizumab.