title: Low socio-economic status is a risk factor for respiratory symptoms: a comparison between Finland, Sweden and Estonia.
abstract: OBJECTIVE
  To assess the relation of socio-economic status to respiratory symptoms common in asthma and chronic bronchitis, and to compare risk factors for these symptoms between three neighbouring countries.
  
  
  METHODS
  A postal survey was performed in 1996 as a part of comparative studies in Finland, Sweden and Estonia (the FinEsS studies). A random sample of 58,661 subjects aged 20-64 years were invited, of whom 44,483 participated.
  
  
  RESULTS
  Respiratory symptoms were most prevalent among manual workers, who were at significantly increased risk for chronic respiratory symptoms. The same pattern of increased risk appeared when the analyses were made among non-smokers only: for recurrent wheeze, manual workers in industry yielded an OR of 1.91 (95%CI 1.62-2.24) and in the service sector an OR of 1.50 (95%CI 1.27-1.78). The corresponding figures for chronic productive cough were 1.45 (95%CI 1.22-1.71) and 1.20 (95%CI 1.02-1.42), respectively. Risk factor profiles for respiratory symptoms were similar in Finland, Sweden and Estonia, except for gender differences in Estonia.
  
  
  CONCLUSIONS
  Belonging to the socio-economic group of manual workers correlated with an increased risk for chronic respiratory symptoms, independently of smoking habits, in each country. Women manual workers in industry suffered most from respiratory symptoms.
authors.affiliation: Department of Medicine/Respiratory Diseases, Helsinki University Central Hospital, Helsinki, Finland. paula.pallasaho@fimnet.fi
authors.forename: P
authors.initials: P
authors.lastname: Pallasaho
authors.forename: M
authors.initials: M
authors.lastname: Lindström
authors.forename: J
authors.initials: J
authors.lastname: Põlluste
authors.forename: Helle-Mai
authors.initials: HM
authors.lastname: Loit
authors.forename: A
authors.initials: A
authors.lastname: Sovijärvi
authors.forename: B
authors.initials: B
authors.lastname: Lundbäck
mesh_terms: D000328:Adult; D001249:Asthma / Q000209:etiology*; D029481:Bronchitis, Chronic / Q000209:etiology*; D003371:Cough / Q000209:etiology*; D004957:Estonia; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D008875:Middle Aged; D012135:Respiratory Sounds / Q000209:etiology*; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking; D012923:Social Class; D013183:Sputum; D011795:Surveys and Questionnaires; D013548:Sweden; D055815:Young Adult