title: The role of economic and educational factors in asthma: evidence from the Portuguese health survey.
abstract: OBJECTIVE
  To evaluate the importance of economic and educational factors in determining the risk of asthma in adults.
  
  
  METHODS
  This was a cross-sectional study in a representative sample of Portuguese adults (20,977 females and 18,663 males) from the main regions of mainland Portugal. Participants were categorized according to years of education (< or = 4, 5-9, 10-12 and >12 years) and income (< or = 314, 315-547, 548-815 and >815Euros/month). Information on asthma was based on answers to the following question: 'Have you had asthma in the previous year?' Logistic regression models were fitted to estimate the magnitude of the association between asthma and education/income, adjusting for confounders (body mass index, age, smoking habits, physical activity, area of residence, number of household members and income/education).
  
  
  RESULTS
  In females and males, the odds of having asthma decreased with increasing income (P-value for trend <0.001), with odds ratios of 0.52 [95% confidence intervals (CI) 0.41-0.66] and 0.55 (95%CI 0.44-0.68) for those with a monthly income >815 Euros compared with those with a monthly income 314 Euros, respectively. For both genders, the odds of having asthma were not significantly associated with years of education.
  
  
  CONCLUSIONS
  A significant positive association between per capita national income and asthma reinforces that public policy should stress the importance of economic growth as a means for preventing asthma occurrence and improving quality of life.
authors.affiliation: Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal. pedromoreira@fcna.up.pt
authors.forename: Pedro
authors.initials: P
authors.lastname: Moreira
authors.forename: André
authors.initials: A
authors.lastname: Moreira
authors.forename: Patrícia
authors.initials: P
authors.lastname: Padrão
authors.forename: Luís
authors.initials: L
authors.lastname: Delgado
mesh_terms: D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000453:epidemiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004522:Educational Status; D015444:Exercise; D005260:Female; D006306:Health Surveys; D006801:Humans; D007182:Income / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D012907:Smoking