title: Hospital-based influenza vaccination of children: an opportunity to prevent subsequent hospitalization.
abstract: OBJECTIVE
  We performed this study to determine the frequency of previous hospitalization among children hospitalized with influenza.
  
  
  METHODS
  The Pediatric Health Information System database (discharges that occurred between January 1, 2001, and December 31, 2006) was used to determine the proportion of children hospitalized with influenza or respiratory illness who had a previous hospitalization during the most recent influenza-vaccination season. Subjects included pediatric patients (through 18 years of age). The index hospitalization was defined as the first influenza or respiratory illness hospitalization for a child that occurred during the study period and between November 1 and April 30. A previous hospitalization during the most recent influenza-vaccination season was defined as a hospitalization for any reason in the 0.5 to 6 months before the index hospitalization but not before September 1 or on or after March 1.
  
  
  RESULTS
  Overall, 16% of children hospitalized with influenza and 12% of children hospitalized with influenza or a respiratory illness had a previous hospitalization during the most recent influenza-vaccination season. Approximately 23% of the children hospitalized with influenza and a comorbidity had a previous hospitalization during the most recent influenza-vaccination season.
  
  
  CONCLUSIONS
  Hospital-based programs for influenza vaccination have the potential to reach children at highest risk of influenza complications and to reduce the rates of pediatric hospitalization for treatment of influenza-related illness.
authors.affiliation: Children's Research Institute, and Children's Hospital and Regional Medical Center, Seattle, WA 98105, USA. danielle.zerr@seattlechildrens.org
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Zerr
authors.forename: Janet A
authors.initials: JA
authors.lastname: Englund
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Robertson
authors.forename: Edgar K
authors.initials: EK
authors.lastname: Marcuse
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Garrison
authors.forename: Dimitri A
authors.initials: DA
authors.lastname: Christakis
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control*; D008297:Male; D012140:Respiratory Tract Diseases / Q000453:epidemiology; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D007252:Influenza Vaccines