Can we improve the targeting of respiratory syncytial virus (RSV) prophylaxis in infants born 32–35 weeks’ gestational age with more informed use of risk factors?

Abstract

Objective: To evaluate the key risk factors for respiratory syncytial virus (RSV) hospitalisation in 32–35 weeks’ gestational age (wGA) infants.

Methods: Published risk factors were assessed for predictive accuracy (area under the receiver operating characteristic curve [ROC AUC]) and for number needed to treat (NNT).

Results: Key risk factors included: proximity of birth to the RSV season; having siblings; crowding at home; day care; smoking; breast feeding; small for GA; male gender; and familial wheezing/eczema. Proximity of birth to the RSV season appeared the most predictive. Risk factors models from Europe and Canada were found to have a high level of predictive accuracy (ROC AUC both >0.75; NNT for European model 9.5). A model optimised for three risk factors (birth ±10 weeks from start of RSV season, number of siblings ≥2 years and breast feeding for ≤2 months) had a similar level of prediction (ROC AUC: 0.776; NNT: 10.2). An example two-risk factor model (day care attendance and living with ≥2 siblings <5 years old) had a lower level of predictive accuracy (ROC AUC: 0.55; NNT: 26).

Conclusions: An optimised combination of risk factors has the potential to improve the identification of 32–35 wGA infants at heightened risk of RSV hospitalisation.

• Bronchiolitis
• hospitalisation
• NNT
• palivizumab
• premature infants

Declaration of interest

X. C-E. and J. F-A. have acted as expert advisors and speakers for AbbVie and have received honoraria in this regard. K. L. G. and P. G. V. are employees of AbbVie. J. R. F. has received fees from AbbVie for work on various projects. AbbVie participated in the interpretation of data, writing, reviewing and approving the publication.

This study was funded by AbbVie, North Chicago, IL.

Authors’ contributions

X. C-E., K. L. G., P. G. V., B. S. R-G. and J. R. F. contributed to the concept and design of the study. J. R. F. carried out the analytical modelling with input from X. C-E., K. L. G., P. G. V. and B. S. R-G., X. C-E. and J. F-A. undertook the clinical interpretation of the data. All authors contributed to the manuscript.