title: Prevalence and risk factors for wheezing in infants in the region of Pamplona, Spain.
abstract: BACKGROUND
  Wheezing in the first year of life affects the baby's and family's quality of life. Risk factors such as male gender, nursery attending or a family history of asthma, and protective factors such as breastfeeding more than six months have been previously described. The aim of this study is to study the prevalence and risk factors for wheezing ever and recurrent wheezing in the first year of life in infants in the region of Pamplona, Spain.
  
  
  METHODS
  This cross-sectional study was part of the International Study of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL). Between 2006 and 2008, participating families answered a standardised validated questionnaire on respiratory symptoms, environmental factors or family issues. An analysis with the chi square test (statistical significance p<0.05) identified the risk factors for wheezing ever and recurrent wheezing, which were assessed using logistic regression.
  
  
  RESULTS
  1065 questionnaires were answered. The prevalence of wheezing ever and recurrent wheezing were 31.2% and 12.3%, respectively. Male gender (p=<0.001), a history of pneumonia (p=<0.001) or nursery attendance (p=<0.001) were some of the risk factors found for wheezing ever. Infant eczema (p=<0.001), nursery attendance (p=<0.001) or prematurity (p=<0.001) were risk factors for recurrent wheezing. No associations with duration of breastfeeding (p=0.116 and p=0.851) or mould stains at home (p=0.153 and p=0.992) were found.
  
  
  CONCLUSIONS
  The study of prevalence and risk factors for wheezing shows the importance of this public health problem, and allows the development of control and treatment strategies against preventable factors.
authors.affiliation: Department of Health Sciences, Public University of Navarre, Pamplona, Spain. Electronic address: alvarez.80114@e.unavarra.es.
authors.forename: I
authors.initials: I
authors.lastname: Alvarez-Alvarez
authors.affiliation: Department of Health Sciences, Public University of Navarre, Pamplona, Spain.
authors.forename: H
authors.initials: H
authors.lastname: Niu
authors.affiliation: Department of Health Sciences, Public University of Navarre, Pamplona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Aguinaga-Ontoso
authors.affiliation: Department of Health Sciences, Public University of Navarre, Pamplona, Spain; IDISNA, Navarra's Institute for Health Research, Pamplona, Spain; Preventive Medicine, University of Navarra Clinic, Pamplona, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Guillen-Grima
mesh_terms: D001249:Asthma / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D004485:Eczema / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009724:Nurseries, Infant; D015995:Prevalence; D012008:Recurrence; D012135:Respiratory Sounds; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: Asthma; Epidemiology; Infant; Prevalence; Risk factors; Wheezing