Trends in respiratory syncytial virus bronchiolitis hospitalizations in children less than 1 year: 2004-2012

Curr Med Res Opin. 2016;32(4):693-8. doi: 10.1185/03007995.2015.1136606. Epub 2016 Feb 3.


Objective: To analyze trends in health outcomes and the influence of risk factors in children under 1 year with acute bronchiolitis due to respiratory syncytial virus (RSV bronchiolitis). A risk-adjustment model for RSV bronchiolitis in-hospital mortality was also developed.

Research design and methods: Retrospective study of hospitalizations for RSV bronchiolitis in children aged <1 year from 2004 to 2012. We used nationally representative data from the Spanish National Health Service records.

Results: Over the study period, the annual hospital discharges for RSV bronchiolitis ranged between 6390 and 8637. The annual in-hospital mortality rate ranged from 120 (2004) to 69 (2012) per 100,000 hospitalizations and the mean length of stay decreased steadily from 6.5 to 5.2 days (p < 0.001); 98.3% of hospitalizations for RSV bronchiolitis were children without risk factors. The in-hospital mortality rate due to RSV bronchiolitis in children with risk factors was 18.8 times higher than non-high-risk children and, in adjusted analyses, the OR of in-hospital mortality due to RSV bronchiolitis was higher than that due to other causes.

Limitations: This study is a retrospective analysis, based on administrative data. It does not include data about pre- or in-hospital treatments, and has the limitations inherent in procedures for determining risk-adjusted mortality rates. Socioeconomic and environmental factors have not been considered in this study.

Conclusions: RSV bronchiolitis is a leading cause of hospitalizations for infants under 1 year and has not shown incidence reduction over a 9 year period. Risk factors increase the in-hospital mortality risk and it is higher if the hospitalization cause is RSV bronchiolitis than any other reason.

Keywords: Bronchiolitis; In-hospital mortality; Readmission; Respiratory syncytial virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Bronchiolitis / epidemiology*
  • Bronchiolitis / virology*
  • Data Collection
  • Hospital Mortality
  • Hospitalization / trends*
  • Humans
  • Incidence
  • Infant
  • Infant, Newborn
  • Length of Stay
  • Models, Theoretical
  • Patient Readmission
  • Respiratory Syncytial Virus Infections / epidemiology*
  • Respiratory Syncytial Viruses*
  • Retrospective Studies
  • Risk Factors
  • Social Class
  • Spain