title: Prevalence and risk factors associated with wheezing in the first year of life.
abstract: OBJECTIVE
  to investigate the prevalence and risk factors associated with wheezing in infants in the first year of life.
  
  
  METHODS
  this was a cross-sectional study, in which a validated questionnaire (Estudio Internacional de Sibilancias en Lactantes--International Study of Wheezing in Infants--EISL) was applied to parents of infants aged between 12 and 15 months treated in 26 of 85 primary health care units in the period between 2006 and 2007. The dependent variable, wheezing, was defined using the following standards: occasional (up to two episodes of wheezing) and recurrent (three or more episodes of wheezing). The independent variables were shown using frequency distribution to compare the groups. Measures of association were based on odds ratio (OR) with a confidence interval of 95% (95% CI), using bivariate analysis, followed by multivariate analysis (adjusted OR [aOR]).
  
  
  RESULTS
  a total of 1,029 (37.7%) infants had wheezing episodes in the first 12 months of life; of these, 16.2% had recurrent wheezing. Risk factors for wheezing were family history of asthma (OR=2.12; 95% CI: 1.76-2.54) and six or more episodes of colds (OR=2.38; 95% CI: 1.91-2.97) and pneumonia (OR=3.02; 95% CI: 2.43-3.76). For recurrent wheezing, risk factors were: familial asthma (aOR=1.73; 95% CI 1.22-2.46); early onset wheezing (aOR=1.83; 95% CI: 1.75-3.75); nocturnal symptoms (aOR=2.56; 95% CI: 1.75-3.75), and more than six colds (aOR=2.07; 95% CI 1.43- .00).
  
  
  CONCLUSIONS
  the main risk factors associated with wheezing in Fortaleza were respiratory infections and family history of asthma. Knowing the risk factors for this disease should be a priority for public health, in order to develop control and treatment strategies.
authors.affiliation: Medicine, Universidade de Fortaleza (UNIFOR), Fortaleza, CE, Brazil. Electronic address: oliviabessa@gmail.com.
authors.forename: Olivia A A Costa
authors.initials: OA
authors.lastname: Bessa
authors.affiliation: Mother-Child Department, School of Medicine, Universidade Federal do Ceará (UFCE), Fortaleza, CE, Brazil.
authors.forename: Álvaro J Madeiro
authors.initials: ÁJ
authors.lastname: Leite
authors.affiliation: Escola Paulista de Medicina, Universidade Federal de São Paulo (EPM-UNIFESP), São Paulo, SP, Brazil.
authors.forename: Dirceu
authors.initials: D
authors.lastname: Solé
authors.affiliation: Department of Pediatric Respiratory Medicine, Hospital El Pino, Universidade do Chile, Santiago, Chile.
authors.forename: Javier
authors.initials: J
authors.lastname: Mallol
mesh_terms: D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016017:Odds Ratio; D011014:Pneumonia / Q000453:epidemiology; D015995:Prevalence; D012135:Respiratory Sounds / Q000209:etiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology*; D012307:Risk Factors; D012737:Sex Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
keywords: Cross-sectional studies; Estudos transversais; Fatores de risco; Infant; Lactente; Prevalence; Prevalência; Risk factors