title: International prevalence of recurrent wheezing during the first year of life: variability, treatment patterns and use of health resources.
abstract: BACKGROUND
  Recurrent wheezing (RW) during the first year of life is a major cause of respiratory morbidity worldwide, yet there are no studies on its prevalence at an international level. A study was undertaken to determine the prevalence of RW in infants during their first year of life in affluent and non-affluent localities.
  
  
  METHODS
  This international population-based study was performed in random samples of infants aged 12-15 months from 17 centres in Latin America and Europe. It uses a validated questionnaire answered by parents at the primary care health clinics where infants attend for growth/development monitoring and/or vaccine administration.
  
  
  RESULTS
  Among the 30,093 infants surveyed, 45.2% (95% CI 44.7% to 45.8%) had at least one episode of wheezing and 20.3% (95% CI 19.8% to 20.7%) had RW. The mean prevalence of RW in Latin American and European centres was 21.4% (95% CI 20.9% to 21.9%) and 15.0% (95% CI 14.0% to 15.9%), respectively (p<0.001). There was significant morbidity associated with RW in terms of severe episodes (59.4%), visits to the emergency department (71.1%) and hospital admissions (26.8%); 46.1% used inhaled corticosteroids.
  
  
  CONCLUSIONS
  The prevalence of RW in infants during the first year of life is high and varies between localities. A significant proportion of infants progress to a more severe condition which results in high use of health resources (visits to emergency department and hospitalisations). The prevalence of RW is lower and less severe in European than in Latin American centres, suggesting there is a higher risk for the disease in developing areas.
authors.affiliation: Department of Pediatric Respiratory Medicine, Hospital El Pino, University of Santiago de Chile, Santiago, Chile. jmallol@vtr.net
authors.forename: Javier
authors.initials: J
authors.lastname: Mallol
authors.forename: Luis
authors.initials: L
authors.lastname: García-Marcos
authors.forename: Dirceu
authors.initials: D
authors.lastname: Solé
authors.forename: Paul
authors.initials: P
authors.lastname: Brand
mesh_terms: D001249:Asthma / Q000453:epidemiology; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004363:Drug Utilization / Q000706:statistics & numerical data; D005060:Europe / Q000453:epidemiology; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007843:Latin America / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012008:Recurrence; D012135:Respiratory Sounds; D019141:Respiratory System Agents / Q000008:administration & dosage; D012140:Respiratory Tract Diseases / Q000188:drug therapy / Q000453:epidemiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology
chemical_list: D019141:Respiratory System Agents