title: Incidence, complications, and risk factors for prolonged stay in children hospitalized with community-acquired influenza.
abstract: OBJECTIVE
  Few studies have examined the characteristics and clinical course of children hospitalized with laboratory-confirmed influenza. We sought to (1) estimate the age-specific incidence of influenza-related hospitalizations, (2) describe the characteristics and clinical course of children hospitalized with influenza, and (3) identify risk factors for prolonged hospitalization.
  
  
  METHODS
  Children < or = 21 years of age hospitalized with community-acquired laboratory-confirmed influenza at a large urban children's hospital were identified through review of laboratory records and administrative data sources. A neighborhood cohort embedded within our study population was used to estimate the incidence of community-acquired laboratory-confirmed influenza hospitalizations among children < 18 years old. Risk factors for prolonged hospitalization (> 6 days) were determined by using logistic regression.
  
  
  RESULTS
  We identified 745 children hospitalized with community-acquired laboratory-confirmed influenza during the 4-year study period. In this urban cohort, the incidence of community-acquired laboratory-confirmed influenza hospitalization was 7 per 10,000 child-years of observation. The median age was 1.8 years; 25% were infants < 6 months old, and 77% were children < 5 years old. Many children (49%) had a medical condition associated with an increased risk of influenza-related complications. The incidence of influenza-related complications was higher among children with a preexisting high-risk condition than for previously healthy children (29% vs 21%). However, only cardiac and neurologic/neuromuscular diseases were found to be independent risk factors for prolonged hospitalization.
  
  
  CONCLUSIONS
  Influenza is a common cause of hospitalization among both healthy and chronically ill children. Children with cardiac or neurologic/neuromuscular disease are at increased risk of prolonged hospitalization; therefore, children with these conditions and their contacts should be a high priority to receive vaccine. The impact on pediatric hospitalization of the new recommendation to vaccinate all children 6 months to < 5 years old should be assessed.
authors.affiliation: Division of General Pediatrics, Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104, USA. coffin@email.chop.edu
authors.forename: Susan E
authors.initials: SE
authors.lastname: Coffin
authors.forename: Theoklis E
authors.initials: TE
authors.lastname: Zaoutis
authors.forename: Anna B Wheeler
authors.initials: AB
authors.lastname: Rosenquist
authors.forename: Kateri
authors.initials: K
authors.lastname: Heydon
authors.forename: Guillermo
authors.initials: G
authors.lastname: Herrera
authors.forename: Carolyn B
authors.initials: CB
authors.lastname: Bridges
authors.forename: Barbara
authors.initials: B
authors.lastname: Watson
authors.forename: Russell
authors.initials: R
authors.lastname: Localio
authors.forename: Richard L
authors.initials: RL
authors.lastname: Hodinka
authors.forename: Ron
authors.initials: R
authors.lastname: Keren
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002673:Child, Hospitalized; D002675:Child, Preschool; D016001:Confidence Intervals; D003428:Cross Infection / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006776:Hospitals, Pediatric; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007251:Influenza, Human / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D007902:Length of Stay / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D011336:Probability; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D013997:Time Factors