Respiratory Syncytial Virus Hospitalization in Infants Born Prematurely and at Term following Respiratory Problems in Early Infancy: Trends Over Time and Impact of Chronological Age

Introduction: Respiratory problems (RPs), such as chronic lung disease, are associated with increased rates of respiratory syncytial virus hospitalization RSVH in young children. This study provides further information on: (1) epidemiology of RP and RSVH over a 12-year period in a national population and (2) RSVH rates in the first versus second year of life in these children.

Materials and Methods: All children with RP (International Classification of Diseases-10 codes: P25, P27.0, P27.1, and Q30–34) born between 2000 and 2011 in NHS Scotland were identified from the Information Services Division datasets. RSVHs (J12.1, J20.5, and J21.0) over the first 2 years of life were assessed.

Results: Of 623,770 children born during the study period, 3,264 (0.52%) were diagnosed with RP. The most common diagnoses were: P25 interstitial emphysema and related conditions (39.8%); Q31 congenital malformations of larynx (24.8%); and P27.1 bronchopulmonary dysplasia (17.6%). Incidence ranged from 0.43 to 0.62% over the study period (p = 0.28). During the first 2 years of life, RSVH incidence was 8.8% (286/3,264) and RSVH rate was 107.2/1,000. Median age at first RSVH was 211 (interquartile range: 105–356) days. RSVH incidence varied annually (range: 6.5–11.8%), with no significant trend over time (p = 0.88). RSVH incidences and rates were 6.6% (216/3,264) and 77.5/1,000, respectively, in the first year of life and 2.5% (83/3,264) and 29.7/1,000 in the second year of life. Intensive care unit (ICU) admissions, length of stay (LOS) in ICU, and overall LOS in hospital decreased with increasing chronological age. RSVH incidences and rates were significantly (p < 0.0001) higher in children with RP than in those without such problems in the first (3.6% [22,626/620,506] and 42.6/1,000) and second (1.2% [7,408/620,506] and 13.6/1,000) year of life.

Conclusion: This study shows that RPs remain a significant risk factor for RSVH in children through 2 years of age, where over a quarter (27.7%) of RSVHs occurred in the second year of life.

Keywords: respiratory syncytial virus; bronchopulmonary dysplasia; chronic lung disease; hospitalization; lung disease

Conflict of Interest: J.C., R.T., and X.C.E. have received research funding and/or compensation as advisor/lecturer from AbbVie. B.R.G. and J.F., working for Strategen, have previously received payment from AbbVie for work on various projects. E.G. is an employee of AbbVie and may hold stock in AbbVie. C.M., working for ISD Scotland, has received payment from AbbVie for work on this project.

Funding: Financial support for this study was provided by AbbVie. AbbVie participated in analysis and interpretation of data, drafting, reviewing, and approving the publication. All authors contributed to the development of the publication and maintained control over the final content.

Acknowledgments: We wish to acknowledge Matthew Freddi, an employee of Strategen Ltd. for medical writing services and David Bailey, an employee of ISD Scotland for services as a data analyst. AbbVie provided funding to Strategen and ISD Scotland for this work.

No conflict of interest has been declared by the author(s).