title: Influenza coinfection and outcomes in children with complicated pneumonia.
abstract: OBJECTIVE
  To determine the impact of influenza coinfection on outcomes for children with complicated pneumonia.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Forty children's hospitals that contribute data to the Pediatric Health Information System.
  
  
  METHODS
  Children discharged from participating hospitals between January 1, 2004, and June 30, 2009, with complicated pneumonia requiring a pleural drainage procedure.
  
  
  METHODS
  Influenza coinfection.
  
  
  METHODS
  Intensive care unit admission, receipt of mechanical ventilation, receipt of vasoactive infusions, receipt of blood product transfusions, in-hospital death, readmission within 14 days of hospital discharge, hospital length of stay, and cost of hospitalization.
  
  
  RESULTS
  Overall, 3382 of 9680 children with complicated pneumonia underwent pleural fluid drainage; 105 patients (3.1%) undergoing pleural drainage had influenza coinfection. A bacterial pathogen was identified in 1201 cases (35.5%); the most commonly identified bacteria were Staphylococcus aureus in children with influenza coinfection (22.9% of cases) and Streptococcus pneumoniae in children without coinfection (20.0% of cases). In multivariable analysis, influenza coinfection was associated with higher odds of intensive care unit admission and receipt of mechanical ventilation, vasoactive infusions, and blood product transfusions as well as higher costs and a longer hospital stay. Children with influenza coinfection were less likely to require readmission, although there was a trend toward higher odds of mortality for patients with coinfection. In a subanalysis stratified by bacteria, outcomes remained worse for coinfected children in the subgroups of children with S aureus and with no specified bacteria.
  
  
  CONCLUSIONS
  Influenza coinfection occurred in 3.1% of children with complicated pneumonia. Clinical outcomes for children with complicated pneumonia and influenza coinfection were more severe than for children without documented influenza coinfection.
authors.affiliation: Division of Pediatric Hospital Medicine, Vanderbilt University School of Medicine and the Monroe Carell Jr Children's Hospital at Vanderbilt, Nashville, Tennessee, USA.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Williams
authors.forename: Matthew
authors.initials: M
authors.lastname: Hall
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Brogan
authors.forename: Reid W D
authors.initials: RW
authors.lastname: Farris
authors.forename: Angela L
authors.initials: AL
authors.lastname: Myers
authors.forename: Jason G
authors.initials: JG
authors.lastname: Newland
authors.forename: Samir S
authors.initials: SS
authors.lastname: Shah
mesh_terms: D017677:Age Distribution; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007251:Influenza, Human / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D015999:Multivariate Analysis; D011023:Pneumonia, Staphylococcal / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D016896:Treatment Outcome; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents; D000998:Antiviral Agents