title: Chronic bronchitis and the type of cigarette smoked.
abstract: BACKGROUND
  Smoking is a well known primary risk factor for chronic bronchitis. However, little is known about the relationship between different types of cigarettes smoked and chronic bronchitis.
  
  
  OBJECTIVE
  To determine the association between chronic bronchitis and the type of cigarette smoked.
  
  
  METHODS
  A cross-sectional prevalence study was conducted in an urban area (Pelotas) of Southern Brazil. A total of 1053 subjects aged > or = 40 years were interviewed about respiratory symptoms and some risk factors for chronic bronchitis.
  
  
  RESULTS
  After adjustment for confounding factors, the number of daily cigarettes smoked was strongly associated with the risk of chronic bronchitis (odds ratio [OR] = 8.10, 95% CI: 4.46-14.71 for smokers of > or = 20 cigarettes per day compared to non-smokers). Among smokers, maize leaf cigarettes showed the highest risk (OR = 5.43 compared to non-smokers, 95% CI: 2.65-11.13) and filter cigarettes the lowest (OR = 2.19, 95% CI: 1.19-4.03).
  
  
  CONCLUSIONS
  In addition to the number of cigarettes smoked, the use of maize leaf cigarettes was shown to have an important independent association with chronic bronchitis.
authors.affiliation: Department of Clinical Medicine, Universidade Federal de Pelotas, RS, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Menezes
authors.forename: C G
authors.initials: CG
authors.lastname: Victora
authors.forename: M
authors.initials: M
authors.lastname: Rigatto
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001938:Brazil; D001991:Bronchitis / Q000453:epidemiology* / Q000209:etiology; D002908:Chronic Disease; D016001:Confidence Intervals; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010947:Plants, Toxic; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D014026:Nicotiana