title: Association between allergic rhinitis and hospital resource use among asthmatic children in Norway.
abstract: BACKGROUND
  Preliminary evidence suggests that inadequately controlled allergic rhinitis in asthmatic patients can contribute towards increased asthma exacerbations and poorer symptom control, which may increase medical resource use. The objective of this study was therefore to assess the effect of concomitant allergic rhinitis on asthma-related hospital resource utilization among children below 15 years of age with asthma in Norway.
  
  
  METHODS
  A population-based retrospective cohort study of children (aged 0-14 years) with asthma was conducted using data from a patient-specific public national database of hospital admissions during a 2-year period, 1998-1999. Multivariate linear regression, adjusting for risk factors including age, gender, year of admission, urban/rural residence and severity of asthma episode, estimated the association between allergic rhinitis and total hospital days. A multivariate Cox proportional-hazards model estimated relative hazard of readmission according to concomitant allergic rhinitis status.
  
  
  RESULTS
  Among 2961 asthmatic children under 15 years of age with at least one asthma-related hospital admission over a 2-year period, 795 (26.8%) had a recorded history of allergic rhinitis. Asthmatic children with allergic rhinitis had a 1.72-times greater hazard of asthma-related readmissions than asthmatic children without allergic rhinitis. Multivariate analysis revealed that history of concomitant allergic rhinitis was a significant predictor of increased number of hospital days per year (least-squares mean difference 0.23 days, P < 0.05).
  
  
  CONCLUSIONS
  Concomitant allergic rhinitis in asthmatic children was associated with increased likelihood of asthma-related hospital readmissions and greater total hospital days.
authors.affiliation: Merck and Co., Whitehouse Station, NJ 08889, USA.
authors.forename: V
authors.initials: V
authors.lastname: Sazonov Kocevar
authors.forename: J
authors.initials: J
authors.lastname: Thomas
authors.forename: L
authors.initials: L
authors.lastname: Jonsson
authors.forename: E
authors.initials: E
authors.lastname: Valovirta
authors.forename: F
authors.initials: F
authors.lastname: Kristensen
authors.forename: D D
authors.initials: DD
authors.lastname: Yin
authors.forename: H
authors.initials: H
authors.lastname: Bisgaard
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications* / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006967:Hypersensitivity / Q000150:complications*; D007223:Infant; D007231:Infant, Newborn; D016018:Least-Squares Analysis; D008297:Male; D015999:Multivariate Analysis; D009664:Norway; D010343:Patient Admission / Q000706:statistics & numerical data; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012220:Rhinitis / Q000209:etiology*