Trends in Respiratory Syncytial Virus and Bronchiolitis Hospitalization Rates in High-Risk Infants in a United States Nationally Representative Database, 1997-2012

PLoS One. 2016 Apr 6;11(4):e0152208. doi: 10.1371/journal.pone.0152208. eCollection 2016.

Abstract

Background: Respiratory syncytial virus (RSV) causes significant pediatric morbidity and is the most common cause of bronchiolitis. Bronchiolitis hospitalizations declined among US infants from 2000‒2009; however, rates in infants at high risk for RSV have not been described. This study examined RSV and unspecified bronchiolitis (UB) hospitalization rates from 1997‒2012 among US high-risk infants.

Methods: The Kids' Inpatient Database (KID) infant annual RSV (ICD-9 079.6, 466.11, 480.1) and UB (ICD-9 466.19, 466.1) hospitalization rates were estimated using weighted counts. Denominators were based on birth hospitalizations with conditions associated with high-risk for RSV: chronic perinatal respiratory disease (chronic lung disease [CLD]); congenital airway anomalies (CAA); congenital heart disease (CHD); Down syndrome (DS); and other genetic, metabolic, musculoskeletal, and immunodeficiency conditions. Preterm infants could not be identified. Hospitalizations were characterized by mechanical ventilation, inpatient mortality, length of stay, and total cost (2015$). Poisson and linear regression were used to test statistical significance of trends.

Results: RSV and UB hospitalization rates were substantially elevated for infants with higher-risk CHD, CLD, CAA and DS without CHD compared with all infants. RSV rates declined by 47.0% in CLD and 49.7% in higher-risk CHD infants; no other declines in high-risk groups were observed. UB rates increased in all high-risk groups except for a 22.5% decrease among higher-risk CHD. Among high-risk infants, mechanical ventilation increased through 2012 to 20.4% and 13.5% of RSV and UB hospitalizations; geometric mean cost increased to $31,742 and $25,962, respectively, and RSV mortality declined to 0.9%.

Conclusions: Among high-risk infants between 1997 and 2012, RSV hospitalization rates declined among CLD and higher-risk CHD infants, coincident with widespread RSV immunoprophylaxis use in these populations. UB hospitalization rates increased in all high-risk groups except higher-risk CHD, suggesting improvement in the health status of higher-risk CHD infants, potentially due to enhanced surgical interventions. Mechanical ventilation use and RSV and UB hospitalization costs increased while RSV mortality declined.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchiolitis / epidemiology
  • Bronchiolitis / therapy*
  • Databases, Factual*
  • Female
  • Hospitalization / statistics & numerical data*
  • Humans
  • Infant
  • Male
  • Respiratory Syncytial Virus Infections / epidemiology
  • Respiratory Syncytial Virus Infections / therapy*
  • United States / epidemiology

Grant support

This research was funded by AstraZeneca. Employees of AstraZeneca (KM, CSA) were involved in the study design, decision to publish, and preparation of the manuscript. The funder provided support in the form of salaries for authors (KM, CSA), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. AstraZeneca provided Epidstat with research support for this study. Employees of Epidstat were involved in the study design (JF), data analysis (AD, XJ, JC), and preparation of the manuscript (AD, XJ, JF, JC). Epidstat provided support in the form of salaries for authors (AD, XJ, JF, JC), but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. Editorial assistance was provided by Complete Healthcare Communications, LLC (Chadds Ford, PA, USA) and funded by AstraZeneca.