title: Prevalence and risk factors for wheezing in Salvador, Brazil: a population-based study.
abstract: BACKGROUND
  Wheezing is one of the most frequent causes of visit to emergency rooms among children. However, data on wheezing burden are mostly provided at healthcare setting, and particularly only for infants.
  
  
  OBJECTIVE
  We sought to estimate the prevalence of wheezing in children under 4 years and to assess potential risk factors in the community.
  
  
  METHODS
  This was a cross-sectional analysis of a population-based cohort study.
  
  
  METHODS
  The sample comprised children aged <4 years living in Salvador, Brazil. Data were collected via home visits when the parents/guardians were interviewed. Data were recorded on standardized forms.
  
  
  RESULTS
  Of 1534 children, mean age was 21 ± 14 months (minimum 3 days; maximum 47 months; 6% <2 months); 780 (51%) were males and 501 [33%; 95% confidence interval (95% CI): 30-35%] reported wheezing in the last 12 months. Among wheezers, 321 (64%) had occasional wheezing. Overall, 180 (12%; 95% CI: 10-14%) had recurrent wheezing and 157 (10%; 95% CI: 9-12%) had asthma. For children in the first, second, third and fourth year of life wheezing was reported in 23, 41, 34 and 37%, respectively. Mother atopic-related disease was independently associated with recurrent wheezing (AdjPR[95% CI]: 1.54 [1.12-2.11]) and asthma (AdjPR[95% CI]: 1.54 [1.10-2.16]). Smoker at home (AdjPR[95% CI]: 1.34 [1.07-1.67]) and low birth weight (AdjPR[95%CI]: 1.38 [1.05-1.81]) were independently associated with occasional wheezing.
  
  
  CONCLUSIONS
  One-third of under 4 years reported wheezing; history of mother's atopic-related disease was an independent risk factor for recurrent wheezing and asthma; smoker at home and low birth weight were independent risk factors for occasional wheezing.
authors.affiliation: From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: G G
authors.initials: GG
authors.lastname: Reis
authors.affiliation: From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: V M
authors.initials: VM
authors.lastname: Miranda
authors.affiliation: From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: M-R A
authors.initials: MR
authors.lastname: Cardoso
authors.affiliation: From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Solé
authors.affiliation: From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Barral
authors.affiliation: From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil From the Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Paediatrics, Federal University of Bahia School of Medicine, Salvador, Brazil, Department of Epidemiology, São Paulo University School of Public Health, São Paulo, Brazil, Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of São Paulo, São Paulo, Brazil and Pathology Department, Federal University of Bahia School of Medicine and Centro de Pesquisa Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil nascimentocarvalho@hotmail.com.
authors.forename: C M
authors.initials: CM
authors.lastname: Nascimento-Carvalho
mesh_terms: D017677:Age Distribution; D001249:Asthma / Q000453:epidemiology; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight / Q000502:physiology; D007231:Infant, Newborn; D008297:Male; D015995:Prevalence; D012008:Recurrence; D012135:Respiratory Sounds / Q000209:etiology*; D012307:Risk Factors; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data
chemical_list: D014028:Tobacco Smoke Pollution