title: Smoking rate and periodontal disease prevalence: 40-year trends in Sweden 1970-2010.
abstract: OBJECTIVE
  To investigate the relationship between smoking rate and periodontal disease prevalence in Sweden.
  
  
  METHODS
  National smoking rates were found from Swedish National Statistics on smoking habits. Based on smoking rates for the years 1970-2010, periodontal disease prevalence estimates were calculated for the age bracket 40-70 years and smoking-associated relative risks between 2.0 and 20.0. The impact of smoking on the population was estimated according to the concept of population attributable fraction.
  
  
  RESULTS
  The age-standardized smoking rate in Sweden declined from 44% in 1970 to 15% in 2010. In parallel with the smoking decline the calculated prevalence estimate of periodontal disease dropped from 26% to 12% assuming a 10-fold smoking-associated relative risk. Even at more moderate magnitudes of the relative risk, e.g. 2-fold or 5-fold, the prevalence decrease was quite tangible, suggesting that the current prevalence in Sweden is about 20-50% of the level 40 years ago. The population attributable fraction, estimating the portion of the disease that would have been avoided in the absence of smoking, was 80% in 1970 and 58% in 2010 at a ten-fold relative risk.
  
  
  CONCLUSIONS
  Calculated estimates of periodontal disease prevalence are closely related to real changes in smoking rate. As smoking rate drops periodontal disease prevalence will drop.
authors.affiliation: Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Bergstrom
mesh_terms: D000328:Adult; D000368:Aged; D017281:Cost of Illness; D006801:Humans; D008875:Middle Aged; D010510:Periodontal Diseases / Q000453:epidemiology*; D015995:Prevalence; D012306:Risk; D012907:Smoking / Q000453:epidemiology*; D013548:Sweden / Q000453:epidemiology
keywords: periodontal disease; population attributable fraction; prevalence; smoking; tobacco