title: Prevalence of respiratory symptoms in migrant children to Italy: the results of SIDRIA-2 study.
abstract: BACKGROUND
  Epidemiological studies have documented large international variations in the prevalence of asthma, and 'westernization' seems to play an important role in the development of the disease. The aims of this study were to compare the prevalence of respiratory symptoms in migrant and nonmigrant children resident in Italy, and to examine the effect of length of time living in Italy.
  
  
  METHODS
  Data were collected in a large cross-sectional study (SIDRIA-2) performed in 12 Italian centres, using standardized parental questionnaires. For the 29 305 subjects included in the analysis (6-7 and 13-14 years old), information about place of birth and parental nationality was available.
  
  
  RESULTS
  There were 1012 children (3%) born outside of Italy, mainly in East Europe. Lifetime asthma and current wheeze were generally significantly less common among children born abroad than among children born in Italy (lifetime asthma: 5.4% and 9.7% respectively, P < 0.001; current wheeze: 5.2% and 6.9%, respectively, P = 0.04). Lower risks for lifetime asthma (prevalence odds ratio, POR = 0.39; 95% CI: 0.23-0.66) and current wheeze (POR = 0.72; 95% CI: 0.47-1.10) were found for children who had lived in Italy <5 years, while migrant children who had lived in Italy for 5 years or more had risks very similar to Italian children.
  
  
  CONCLUSIONS
  Migrant children have a lower prevalence of asthma symptoms than children born in Italy. Prevalence increased with the number of years of living in Italy, suggesting that exposure to environmental factors may play an important role in the development of asthma in childhood.
authors.affiliation: Cancer Epidemiology Unit, San Giovanni Battista Hospital - Center for Cancer Prevention Piemonte (CPO), Turin, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Migliore
authors.forename: N
authors.initials: N
authors.lastname: Pearce
authors.forename: M
authors.initials: M
authors.lastname: Bugiani
authors.forename: G
authors.initials: G
authors.lastname: Galletti
authors.forename: A
authors.initials: A
authors.lastname: Biggeri
authors.forename: L
authors.initials: L
authors.lastname: Bisanti
authors.forename: N
authors.initials: N
authors.lastname: Caranci
authors.forename: V
authors.initials: V
authors.lastname: Dell'Orco
authors.forename: M
authors.initials: M
authors.lastname: De Sario
authors.forename: P
authors.initials: P
authors.lastname: Sestini
authors.forename: S
authors.initials: S
authors.lastname: Piffer
authors.forename: G
authors.initials: G
authors.lastname: Viegi
authors.forename: F
authors.initials: F
authors.lastname: Forastiere
authors.forename: C
authors.initials: C
authors.lastname: Galassi
authors.forename: G
authors.initials: G
authors.lastname: Ciccone
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D004641:Emigration and Immigration; D006801:Humans; D007558:Italy / Q000453:epidemiology; D015995:Prevalence; D012135:Respiratory Sounds; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013997:Time Factors